JEE Physics

StemEZ

Chapter 13

Magnetic Effects Of Electric Current And Magnetism - all with Video Answers

Educators

AK

Chapter Questions

Problem 1861

An element $\mathrm{d} \ell^{-}=\mathrm{dx} \uparrow$ (where $\mathrm{dx}=1 \mathrm{~cm}$ ) is placed at the origin and carries a large current $\mathrm{I}=10 \mathrm{Amp}$. What is the mag. field on the Y-axis at a distance of $0.5$ meter ?
(a) $2 \times 10^{-8} \mathrm{k} \wedge \mathrm{T}$
(b) $4 \times 10^{8} \mathrm{k} \wedge \mathrm{T}$
(c) $-2 \times 10^{-8} \mathrm{k} \wedge \mathrm{T}$
(d) $-4 \times 10^{-8} \mathrm{k} \wedge \mathrm{T}$

Ankur S

Ankur S

Numerade Educator

Problem 1862

Two straight long conductors $\mathrm{AOB}$ and $\mathrm{COD}$ are perpendicular to each other and carry currents $\mathrm{I}_{1}$ and $\mathrm{I}_{2}$. The magnitude of the mag. field at a point " $\mathrm{P}^{n}$ at a distance " $\mathrm{a}^{\prime \prime}$ from the point "O" in a direction perpendicular to the plane $\mathrm{ABCD}$ is
(a) $\left[\left(\mu_{0}\right) /(2 \pi a)\right]\left(I_{1}+I_{2}\right)$
(b) $\left[\left(\mu_{0}\right) /(2 \pi a)\right]\left(I_{1}-I_{2}\right)$
(c) $\left[\left(\mu_{0}\right) /(2 \pi a)\right]\left(\mathrm{I}_{1}^{2}+\mathrm{I}_{2}^{2}\right)^{1 / 2}$
(d) $\left[\left(\mu_{0}\right) /(2 \pi a)\right]\left[\left(I_{1} I_{2}\right) /\left(I_{1}-I_{2}\right)\right]$

Narayan Hari

Numerade Educator

Problem 1863

$\mathrm{B} \rightarrow \mathrm{R}$ graph. The mag. field $\mathrm{B}$ at a distance $\mathrm{r}$ from a long straight wire carrying a current varies with $\mathrm{r}$ as shown in Fig.

Narayan Hari

Numerade Educator

Problem 1864

A current path shaped as shown in figure produces a mag. field at point " $\mathrm{P}^{\prime \prime}$, the centre at the arc $\mathrm{BC}$. If the arc subtends an angle of $30^{\circ}$ and the radius of the arc is $0.6$ meter. What is the magnitude of the field at point $P$ if the current is 3 AMP?
(a) $2.62 \times 10^{-6} \mathrm{~T}$
(b) $2.62 \times 10^{-7} \mathrm{~T}$
(c) $3.62 \times 10^{-7} \mathrm{~T}$
(d) $2.62 \times 10^{-8} \mathrm{~T}$

Narayan Hari

Numerade Educator

Problem 1865

As shown in figure a conductor carrying a current I. Find the magnetic field intensity at the point "O".
(a) $(5 / 24)\left(\mu_{0} / \pi\right) \times(1 / r) \theta k \wedge$
(b) $[(-5) / 26]\left(\mu_{0} / \pi\right)(1 / r) \theta \mathrm{k} \wedge$
(c) $[(-7) / 24]\left(\mu_{0} / \pi\right)(1 / r) \theta k$
(d) $-(5 / 24)\left(\mu_{0} / \pi\right)(1 / \mathrm{r}) \theta \mathrm{k} \wedge$

Aja S

Numerade Educator

Problem 1866

A length L of wire carries a steady current $1 .$ It is bent first to form a coil of 1 turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current is
(a) A quater of its first value
(b) Un changed
(c) Four times of its first value
(d) A half of its first value

Narayan Hari

Numerade Educator

Problem 1867

If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
(a) Only inside the pipe
(b) Only outside the pipe
(c) Neither inside nor outside the pipe
(d) Both inside and outside the pipe

Narayan Hari

Numerade Educator

Problem 1868

The magnetic induction at a point $P$ which is at a distance $4 \mathrm{~cm}$ from a long current carrying wire is $10^{-8}$ tesla. The field of induction at a distance $12 \mathrm{~cm}$ from the same current would be tesla.
(a) $3.33 \times 10^{-9}$
(b) $1.11 \times 10^{-4}$
(c) $3 \times 10^{-3}$
(d) $9 \times 10^{-2}$

Narayan Hari

Numerade Educator

Problem 1869

The strength of the magnetic field at a point $\mathrm{y}$ near a long straight current carrying wire is $\mathrm{B}$. The field at a distance $\mathrm{y} / 2$ will be
(a) B/2
(b) B $/ 4$
(c) $2 \mathrm{~B}$
(d) $4 \mathrm{~B}$

Narayan Hari

Numerade Educator

Problem 1870

The mag. field (B) at the centre of a circular coil of radius "a", through which a current I flows is
(a) $\mathrm{B} \propto \mathrm{c} \mathrm{a}$
(b) $\mathrm{B} \propto(1 / \mathrm{I})$
(c) $\mathrm{B} \propto \mathrm{I}$
(d) $B \propto I^{2}$

Narayan Hari

Numerade Educator

Problem 1871

A current of a $1 \mathrm{Amp}$ is passed through a straight wire of length 2 meter. The magnetic field at a point in air at a distance of 3 meters from either end of wire and lying on the axis of wire will be
(a) $\left(\mu_{0} / 2 \pi\right)$
(b) $\left(\mu_{0} / 4 \pi\right)$
(c) $\left(\mu_{0} / 8 \pi\right)$
(d) zero

Narayan Hari

Numerade Educator

Problem 1872

If the strength of the magnetic field produced at $10 \mathrm{~cm}$ away from a infinitely long straight conductor is $10^{-5}$ tesla. The value of the current flowing in the conductor will be Ampere.
(a) 5
(b) 10
(c) 500
(d) 1000

Narayan Hari

Numerade Educator

Problem 1873

A long straight wire of radius "a" carries a steady current I the current is uniformly distributed across its cross-section. The ratio of the magnetic field at $\mathrm{a} / 2$ and $2 \mathrm{a}$ is
(a) $(1 / 4)$
(b) 4
(c) 1
(d) $(1 / 2)$

Narayan Hari

Numerade Educator

Problem 1874

At a distance of $10 \mathrm{~cm}$ from a long straight wire carrying current, the magnetic field is $4 \times 10^{-2}$. At the distance of $40 \mathrm{~cm}$, the magnetic field will be Tesla.
(a) $1 \times 10^{-2}$
(b) $2 \times \overline{10^{-2}}$
(c) $8 \times 10^{-2}$
(d) $16 \times 10^{-2}$

Narayan Hari

Numerade Educator

Problem 1875

As shown in figure $\mathrm{ABCD}$ and $\mathrm{CDEF}$ planes are kept carrying current I. Each side of the plane is having length " $2 \mathrm{a}^{\prime \prime}$. The magnetic field due to $\mathrm{ABCD}$ and $\mathrm{CDEF}$ planes at the point $\mathrm{P}(\mathrm{a}, 0, \mathrm{a})$ is in the direction.
(a) $[(-i \wedge+k \wedge) / \sqrt{2}]$
(b) $[(i \wedge-j \wedge+k \wedge) / \sqrt{3}]$
(c) $[(i \wedge+j \wedge+k \wedge) / \sqrt{3}]$
(d) $[(i \wedge+k) / \sqrt{2}]$

Narayan Hari

Numerade Educator

Problem 1876

A He nucleus makes a full rotation in a circle of radius $0.8$ meter in $2 \mathrm{sec}$. The value of the mag. field $\mathrm{B}$ at the centre of the circle will be $\quad$ Tesla.
(a) $\left(10^{-19} / \mu_{0}\right)$
(b) $10^{-19} \mu_{0}$
(c) $2 \times 10^{-10} \mathrm{H}_{0}$
(d) $\left[\left(2 \times 10^{-10}\right) / \mu_{0}\right]$

Narayan Hari

Numerade Educator

Problem 1877

The magnetic at pt. "O" in the figure shown is Where $\mathrm{AB}=\mathrm{CD}=2 \mathrm{~cm}$
$$
\begin{aligned}
&\mathrm{R}_{1}=10 \mathrm{~cm} \\
&\mathrm{R}_{2}=12 \mathrm{~cm} \\
&\mathrm{I}=4 \mathrm{Amp}
\end{aligned}
$$

Carolyn Shasha

Numerade Educator

Problem 1878

As shown in Fig. there are two semicircles of radii $\mathrm{r}_{1}=12 \mathrm{~cm}$ and $r_{2}=10 \mathrm{~cm}$ in which 4 Amp current is following The mag. field at the centre ${ }^{n} \mathrm{O}^{n}$ is(a) $(55 / 3) \mu_{0}$ going inside
(b) $(3 / 55) \mu_{0}$ going outside
(c) $(6 / 55) \mu_{0}$ going inside
(d) $(12 / 55) \mu_{0}$ going inside

Narayan Hari

Numerade Educator

Problem 1879

The direction of mag. field lines close to a straight conductor carrying current will be
(a) Along the length of the conductor
(b) Radially outward
(c) Circular in a plane perpendicular to the conductor
(d) Helical

Narayan Hari

Numerade Educator

Problem 1880

0: Due to 10 Amp of current flowing in a circular coil of $10 \mathrm{~cm}$ radius, the mag. field produced at its centre is $\pi \times 10^{-3}$ Tesla. The number of turns in the coil will be
(a) 5000
(b) 100
(c) 50
(d) 25

Narayan Hari

Numerade Educator

Problem 1881

There are 50 turns $/ \mathrm{cm}$ in a long solenoid. If 4 Amp current is flowing in the solenoid, the approximate value of mag. field along its axis at an internal point and one end will be respectively.
(a) $12.6 \times 10^{-3}$ Tesla; $6.3 \times 10^{-3}$ tesla
(b) $12.6 \times 10^{-3}$ Tesla; $25.1 \times 10^{-3}$ tesla
(c) $25.1 \times 10^{-3}$ Tesla; $12.6 \times 10^{-3}$ tesla
(d) $25.1 \times 10^{-5}$ Tesla $; 6.3 \times 10^{-5}$ tesla

Narayan Hari

Numerade Educator

Problem 1882

The distance at which the magnetic field on axis as compared to the mag. field at the centre of the coil carrying current I and radius $R$ is (1/8), would be
(a) $R$
(b) $\sqrt{2} \mathrm{R}$
(c) $2 \mathrm{R}$
(d) $\sqrt{3} \mathrm{R}$

AK

Ankur Khosla

Numerade Educator

Problem 1883

In a H-atom, an electron moves in a circular orbit of radius $5.2 \times 10^{-11}$ meter and produces a mag. field of $12.56$ Tesla at its nucleus. The current produced by the motion of the electron will be
(a) $6.53 \times 10^{-3}$
(b) $13.25 \times 10^{-10}$
(c) $9.6 \times 10^{6}$
(d) $1.04 \times 10^{-3}$

Narayan Hari

Numerade Educator

Problem 1884

A conducting rod of 1 meter length and $1 \mathrm{~kg}$ mass is suspended by two vertical wires through its ends. An external magnetic field of 2 Tesla is applied normal to the rod. Now the current to be passed through the rod so as to make the tension in the wires zero is [take $\left.\mathrm{g}=10 \mathrm{~ms}^{-2}\right]$
(a) $0.5 \mathrm{Amp}$
(b) $15 \mathrm{Amp}$
(c) $5 \mathrm{Amp}$
(d) $1.5 \mathrm{Amp}$

Narayan Hari

Numerade Educator

Problem 1885

A straight wire of mass $200 \mathrm{gm}$ and length $1.5$ meter carries a current of 2 Amp. It is suspended in mid-air by a uniform horizontal magnetic field B. [take $\left.\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}\right]$. The $\mathrm{B}$ is
(a) $\overline{(2 / 3) \text { tes } 1 a}$
(b) $(3 / 2)$ tesla
(c) $(20 / 3)$ tesla
(d) (3/20) tesla

Narayan Hari

Numerade Educator

Problem 1886

A long solenoid has 200 turns per $\mathrm{cm}$ and carries a current of $2.5 \mathrm{Amp}$. The mag. field at its centre is tesla.
(a) $\pi \times 10^{-2}$
(b) $2 \pi \times 10^{-2}$
(c) $3 \pi \times 10^{-2}$
(d) $4 \pi \times 10^{-2}$

Narayan Hari

Numerade Educator

Problem 1887

Two concentric co-planar circular Loops of radii $\mathrm{r}_{1}$ and $\mathrm{r}_{2}$ carry currents of respectively $\mathrm{I}_{1}$ and $\mathrm{I}_{2}$ in opposite directions. The magnetic induction at the centre of the Loops is half that due to $\mathrm{I}_{1}$ alone at the centre. If $\mathrm{r}_{2}=2 \mathrm{r}_{1}$ the value of $\left(\mathrm{I}_{2} / \mathrm{I}_{1}\right)$ is
(a) 2
(b) $1 / 2$
(c) $1 / 4$
(d) 1

Narayan Hari

Numerade Educator

Problem 1888

Circular loop of a wire and a long straight wire carrying current $\mathrm{I}_{\mathrm{C}}, \mathrm{I}_{\mathrm{E}}$ respectively as shown in fig. Assuming that these are placed in the same plane. The mag. field will be zero at the centre of the Loop when separation $\mathrm{H}$ is
(a) $\left[\left(\mathrm{I}_{\mathrm{e}} \mathrm{R}\right) /\left(\mathrm{I}_{c} \pi\right)\right]$
(b) $\left[\left(\mathrm{I}_{\mathrm{c}} \mathrm{R}\right) /\left(\mathrm{I}_{\mathrm{e}} \pi\right)\right]$
(c) $\left[\left(\pi \mathrm{I}_{\mathrm{c}}\right) /\left(\mathrm{I}_{\mathrm{e}} \mathrm{R}\right)\right]$
(d) $\left[\left(\mathrm{I}_{\mathrm{e}} \pi\right) /\left(\mathrm{I}_{\mathrm{c}} \mathrm{R}\right)\right]$

Ajay Singhal

Numerade Educator

Problem 1889

For the mag. field to be maximum due to a small element of current carrying conductor at a point, the angle between the element and the line joining the element to the given point must be
(a) $0^{\circ}$
(b) $90^{\circ}$
(c) $180^{\circ}$
(d) $45^{\circ}$

Narayan Hari

Numerade Educator

Problem 1891

A long straight wire carrying current of $30 \mathrm{Amp}$ is placed in an external uniform mag. field of induction $4 \times 10^{-4}$ tesla. The mag. field is acting parallel to the direction of current. The magnitude of the resultant magnetic induction in tesla at a point $2 \mathrm{~cm}$ away from the wire is tesla.
(a) $10^{-4}$
(c) $5 \times 10^{-4}$
(b) $3 \times 10^{-4}$
(d) $6 \times 10^{-4}$

Narayan Hari

Numerade Educator

Problem 1892

Two similar coils are kept mutually perpendicular such that their centers co-inside. At the centre, find the ratio of the mag. field due to one coil and the resultant magnetic field by both coils, if the same current is flown.
(a) $1: \sqrt{2}$
(b) $1: 2$
(c) $2: 1$
(d) $\sqrt{3}: 1$

Narayan Hari

Numerade Educator

Problem 1893

A long wire carr1es a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is $\mathrm{B}$. It is then bent into a circular Loop of n turns. The magnetic field at the centre of the coil for same current will be.
(a) $\mathrm{nB}$
(b) $\mathrm{n}^{2} \mathrm{~B}$
(c) $2 \mathrm{nB}$
(d) $2 \mathrm{n}^{2} \mathrm{~B}$

Narayan Hari

Numerade Educator

Problem 1894

The mag. field due to a current carrying circular Loop of radius $3 \mathrm{~cm}$ at a point on the axis at a distance of $4 \mathrm{~cm}$ from the centre is $54 \mu \mathrm{T}$ what will be its value at the centre of the LOOP.
(a) $250 \mu \mathrm{T}$
(b) $150 \mu \mathrm{T}$
(c) $125 \mu \mathrm{T}$
(d) $75 \mu \mathrm{T}$

Aja S

Numerade Educator

Problem 1895

5: When the current flowing in a circular coil is doubled and the number of turns of the coil in it is halved, the magnetic field at its centre will become
(a) Four times
(b) Same
(c) Half
(d) Double

Narayan Hari

Numerade Educator

Problem 1896

Two wires of same length are shaped into a square and a circle. If they carry same current, ratio of the magnetic moment is
(a) $2: \pi$
(b) $\pi: 2$
(c) $\pi: 4$
(d) $4: \pi$

Vysakh M

Numerade Educator

Problem 1897

Two concentric coils each of radius equal to $2 \pi \mathrm{cm}$ are placed at right angles to each other. 3 Amp and $4 \mathrm{Amp}$ are the currents flowing in each coil respectively. The magnetic field intensity at the centre of the coils will be Tesla.
(a) $5 \times 10^{-5}$
(b) $7 \times 10^{-5}$
(c) $12 \times 10^{-5}$
(d) $10^{-5}$

Narayan Hari

Numerade Educator

Problem 1898

Two parallel long wires $\mathrm{A}$ and B carry currents $\mathrm{I}_{1}$ and $\mathrm{I}_{2}$. $\left(\mathrm{I}_{2}<\mathrm{I}_{1}\right)$ when $\mathrm{I}_{1}$ and $\mathrm{I}_{2}$ are in the same direction the mag. field at a point mid way between the wires is $10 \mu \mathrm{T}$. If $\mathrm{I}_{2}$ is reversed, the field becomes $30 \mu \mathrm{T}$. The ratio $\left(\mathrm{I}_{1} / \mathrm{I}_{2}\right)$ is
(a) 1
(b) 2
(c) 3
(d) 4

Ankur S

Numerade Educator

Problem 1899

Two parallel long straight conductors are placed at right angle to the meter scale at the $2 \mathrm{~cm}$ and $6 \mathrm{~cm}$ marks as shown in the figure. If they carry currents I and $3 \mathrm{I}$ respectively in the upward direction, then will produce zero magnetic field at

Ankur S

Numerade Educator

Problem 1900

A long s ru nas 800 turns per meter length or soleflore. A current of $1.6$ Amp flows through it. The magnetic induction at the end of the solenoid on its axis is tesla.
(a) $16 \times 10^{-4}$
(b) $8 \times 10^{-4}$
(c) $32 \times 10^{-4}$
(d) $4 \times 10^{-4}$

Narayan Hari

Numerade Educator

Problem 1901

A solenoid of $1.5$ meter length and $4 \mathrm{~cm}$ diameter possesses 10 turn per $\mathrm{cm}$. A current of $5 \mathrm{Amp}$ is flowing through it. The magnetic induction at axis inside the solenoid is
(a) $2 \pi \times 10^{-3} \mathrm{~T}$
(b) $2 \pi \times 10^{-5} \mathrm{~T}$
(c) $2 \pi \times 10^{-2} \mathrm{G}$
(d) $2 \pi \times 10^{-5} \mathrm{G}$

Narayan Hari

Numerade Educator

Problem 1902

A straight wire of length $30 \mathrm{~cm}$ and mass 60 milligram lies in
a direction $30^{\circ}$ east of north. The earth's magnetic field at this site is horizontal and has a magnitude of $0.8 \mathrm{G}$. What current must be passed through the wire so that it may float in air ? $\left[\mathrm{g}=10\left(\mathrm{~m} / \mathrm{s}^{2}\right)\right]$
(a) $10 \mathrm{Amp}$
(b) $20 \mathrm{Amp}$
(c) $40 \mathrm{Amp}$
(d) $50 \mathrm{Amp}$

Vishal Gupta

Numerade Educator

Problem 1903

A long horizontal wire " $\mathrm{A}^{\prime \prime}$ carries a current of $50 \mathrm{Amp}$. It is rigidly fixed. Another small wire "B" is placed just above and parallel to " $\mathrm{A}^{\prime \prime}$. The weight of wire- $\mathrm{B}$ per unit length is $75 \times 10^{-3}$ Newton/meter and carries a current of 25 Amp. Find the position of wire $B$ from $A$ so that wire $B$ remains suspended due to magnetic repulsion. Also indicate the direction of current in $B$ w.r.t. to $A$.(a) $(1 / 2) \times 10^{-2} \mathrm{~m}$; in same direction
(b) $(1 / 3) \times 10^{-2} \mathrm{~m}$; in mutually opposite direction
(c) $(1 / 4) \times 10^{-2} \mathrm{~m}$; in same direction
(d) $(1 / 5) \times 10^{-2} \mathrm{~m}$; in mutually opposite direction

Narayan Hari

Numerade Educator

Problem 1904

A circular loop of radius $\mathrm{R}=20 \mathrm{~cm}$ is placed in a uniform magnetic field $\mathrm{B}=2$ Tesla in $\mathrm{xy}$ - Plane as shown in figure. The loop carries a current $\mathrm{I}=1$ Amp in the direction shown in fig. Find the magnitude of torque acting on the Loop.(a) $0.15 \mathrm{~N} / \mathrm{m}$
(b) $0.25 \mathrm{~N} / \mathrm{m}$
(c) $0.55 \mathrm{~N} / \mathrm{m}$
(d) $0.35 \mathrm{~N} / \mathrm{m}$

Narayan Hari

Numerade Educator

Problem 1905

The rectangular coil having 100 turns is turned in a uniform mag. field of $[(0.05) / \sqrt{2}] \mathrm{J} \Lambda$ as shown in the fig. The torque acting on the Loop is(a) $11.32 \times 10^{-4} \mathrm{~N} \cdot \mathrm{m} \cdot \mathrm{k} /$
(b) $22.64 \times 10^{-4} \mathrm{~N}-\mathrm{m} \cdot \mathrm{k} /$
(c) $5.66 \times 10^{-3} \mathrm{~N} \cdot \mathrm{m} \cdot \mathrm{k} \wedge$
(d) zero

Narayan Hari

Numerade Educator

Problem 1906

Two particles $\mathrm{X}$ and $\mathrm{Y}$ having equal charges, after being accelerated through the same potential difference, enter a region of uniform mag. field and describe circular path of radius $\mathrm{r}_{1}$ and $\mathrm{r}_{2}$ respectively. The ratio of mass of $\mathrm{X}$ to that of $\mathrm{Y}$ is
(a) $\sqrt{\left(r_{1} / \mathrm{r}_{2}\right)}$
(b) $\left(\mathrm{r}_{2} / \mathrm{r}_{1}\right)$
(c) $\left(\mathrm{r}_{1} / \mathrm{r}_{2}\right)^{2}$
(b) $\left(\mathrm{r}_{1} / \mathrm{r}_{2}\right)$

Aja S

Numerade Educator

Problem 1907

An electron having mass $9 \times 10^{-31} \mathrm{~kg}$, charge $1.6 \times 10^{-19} \mathrm{C}$ and moving with a velocity of $10^{6} \mathrm{~m} / \mathrm{s}$ enters a region where mag. field exists. If it describes a circle of radius $0.10 \mathrm{~m}$, the intensity of magnetic field must be Tesla
(a) $1.8 \times 10^{-4}$
(b) $5.6 \times \overline{10^{-5}}$
(c) $14.4 \times 10^{-5}$
(d) $1.3 \times 10^{-6}$

Narayan Hari

Numerade Educator

Problem 1908

A proton and an particle are projected with the same kinetic energy at right angles to the uniform mag. field. Which one of the following statements will be true.
(a) The $\alpha$ - particle will be bent in a circular path with a small radius that for the proton.
(b) The radius of the path of the $\alpha$ - particle will be greater than that of the proton.
(c) The $\alpha$ - particle and the proton will be bent in a circular path with the same radius.
(d) The $\alpha$ - particle and the proton will go through the field in
a straight line.

Hunza Gilgit

Numerade Educator

Problem 1909

A 2 Mev proton is moving perpendicular to a uniform magnetic field of $2.5$ tesla. The force on the proton is
(a) $3 \times 10^{-10} \mathrm{~N}$
(b) $70.8 \times 10^{-11} \mathrm{~N}$
(c) $3 \times 10^{-11} \mathrm{~N}$
(d) $7.68 \times 10^{-12} \mathrm{~N}$

Narayan Hari

Numerade Educator

Problem 1910

A proton is projected with a speed of $2 \times 10^{6}(\mathrm{~m} / \mathrm{s})$ at an angle of $60^{\circ}$ to the $\mathrm{X}$ -axis. If a uniform mag. field of $0.104$ tesla is applied along $\mathrm{Y}$ -axis, the path of proton is
(a) A circle of $\mathrm{r}=0.2 \mathrm{~m}$ and time period $\pi \times 10^{-7} \mathrm{sec}$
(b) A circle of $\mathrm{r}=0.1 \mathrm{~m}$ and time period $2 \pi \times 10^{-7} \mathrm{sec}$
(c) A helix of $r=0.1 \mathrm{~m}$ and time period $2 \pi \times 10^{-7} \mathrm{sec}$
(d) A helix of $\mathrm{r}=0.2 \mathrm{~m}$ and time period $4 \pi \times 10^{-7} \mathrm{sec}$

Aja S

Numerade Educator

Problem 1911

1: A charged particle moves in a uniform mag. field. The velocity of the particle at some instant makes an acute angle with the mag. field. The path of the particle will be
(a) A straight line
(b) A circle
(c) A helix with uniform pitch
(d) A helix with non-uniform pitch

Narayan Hari

Numerade Educator

Problem 1912

$A$, proton, a deuteron and $a$ -an particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field. If $\mathrm{r}_{\mathrm{p}} \mathrm{r}_{\mathrm{d}}$ and denote respectively the radii of trajectories of these particles, then
(a) $\mathrm{r}_{\alpha}=\mathrm{r}_{\mathrm{p}}<\mathrm{r}_{\mathrm{d}}$
(b) $\mathrm{r}_{\alpha}>\mathrm{r}_{\mathrm{d}}>\mathrm{r}_{\mathrm{p}}$
(c) $\mathrm{r}_{0}=\mathrm{r}_{\mathrm{d}}>\mathrm{r}_{n}$
(d) $\mathrm{r}_{n}=\mathrm{r}_{\mathrm{d}}=\mathrm{r}_{1}$

Narayan Hari

Numerade Educator

Problem 1913

Two particles $\mathrm{A}$ and $\mathrm{B}$ of masses $\mathrm{m}_{\mathrm{A}}$ and $\mathrm{m}_{\mathrm{B}}$ respectively and having the same charge are moving in a plane. $\mathrm{A}$ uniform mag. field exists perpendicular to this plane. The speeds of the particles are $\mathrm{V}_{\mathrm{A}}$ and $\mathrm{V}_{\mathrm{B}}$ respectively and the trajectories are as shown in the figure, then.

Narayan Hari

Numerade Educator

Problem 1914

An electron and a proton with equal momentum enter perpendicularly into a uniform magnetic then.
(a) The path of proton shall be more curved than that of electron.
(b) The path of proton shall be less curved turn that of electron.
(c) Both are equally curved.
(d) Path of both will be straight line.

Narayan Hari

Numerade Educator

Problem 1915

A current $\mathrm{I}$, carrying wire $\mathrm{AB}$ is placed near an another long wire CD carrying current $\mathrm{I}_{2}$ As shown in Fig. If free to move, wire AB will have(a) rotational motion only
(b) translational motion only
(c) rotational as well as translational motion
(d) neither rotational nor translational motion

Narayan Hari

Numerade Educator

Problem 1916

A conducting rod of length $\ell$ [cross-section is shown] and mass $\mathrm{m}$ is moving down on a smooth inclined plane of inclination $\theta$ with constant speed v. A vertically upward mag. field $\mathrm{B}^{-}$ exists in upward direction. The magnitude of mag. field $B^{-}$ is(a) $[(\mathrm{mg} \sin \theta) /(\mathrm{I} \ell)]$
(b) $[(\mathrm{mg} \cos \theta) /(\mathrm{I} \ell)]$
(c) $[(\mathrm{mg} \tan \theta) /(\mathrm{I} \ell)]$
(d) $[(\mathrm{mg}) /(\mathrm{I} \ell \sin \theta)]$

Narayan Hari

Numerade Educator

Problem 1917

A neutron of $K$. E. 50 ev is describing a circular orbit of radius $0.5 \mathrm{~m}$ in a plane perpendicular to magnetic field $\mathrm{B}^{-}$. The $\mathrm{K} . \mathrm{E}$. of the proton that describe a circular orbit of radius
$0.5 \mathrm{~m}$ in the same plane with the same $\mathrm{B}^{-}$ is
(a) $200 \mathrm{ev}$
(b) $100 \mathrm{ev}$
(c) $50 \mathrm{ev}$
(d) $25 \mathrm{ev}$

Ankur S

Numerade Educator

Problem 1918

A magnetic field existing in a region is given by $\mathrm{B}^{-}=\mathrm{B}_{0}[1+(\mathrm{x} / \ell)] \mathrm{k} \wedge . \mathrm{A}$ square loop of side $\ell$ and carrying
current I is placed with edges (sides) parallel to $\mathrm{X}-\mathrm{Y}$ axis. The magnitude of the net magnetic force experienced by the Loop is
(a) $2 \mathrm{~B}_{0} \overline{\mathrm{I} \ell}$
(b) $(1 / 2) B_{0} I \ell$
(c) $\mathrm{B}_{\circ} \mathrm{I} \ell$
(d) BI\ell

Saman Zulfiqar

Numerade Educator

Problem 1919

The forces existing between two parallel current carrying conductors is $\mathrm{F}$. If the current in each conductor is doubled, then the value of force will be
(a) $2 \mathrm{~F}$
(b) $4 \mathrm{~F}$
(c) $5 \mathrm{~F}$
(d) $(\mathrm{F} / 2)$

Narayan Hari

Numerade Educator

Problem 1920

At a given place the horizontal component of earth's field is $0.2 \mathrm{G}$. If a vertical wire carries a current of 30 Amp upward, what is the magnitude and direction of the force on 1 meter of wire?
(a) $6 \mathrm{E}$ to $\mathrm{W}$
(b) $6 \times 10^{-3} \mathrm{E}$ to $\mathrm{W}$
(c) $6 \times 10^{-3} \mathrm{E}$ to $\mathrm{W}$
(d) $6 \times 10^{-4} \mathrm{E}$ to $\mathrm{W}$

Narayan Hari

Numerade Educator

Problem 1921

A Galvanometer has a resistance $\mathrm{G}$ and $\mathrm{Q}$ current $\mathrm{I}_{\mathrm{G}}$ flowing in it produces full scale deflection. $\mathrm{S}_{1}$ is the value of the shunt which converts it into an ammeter of range 0 to $\mathrm{I}$ and $\mathrm{S}_{2}$ is the value of the shunt for the range 0 to $2 \mathrm{I}$. The ratio $\left(\mathrm{S}_{1} / \mathrm{S}_{2}\right) \mathrm{is}$
(a) $\left[\left(2 \mathrm{I}-\mathrm{I}_{\mathrm{G}}\right) /\left(\mathrm{I}-\mathrm{I}_{\mathrm{G}}\right)\right]$
(b) $(1 / 2)\left[\left(\mathrm{I}-\mathrm{I}_{\mathrm{G}}\right) /\left(2 \mathrm{I}-\mathrm{I}_{\mathrm{G}}\right)\right]$
(c) 2
(d) 1

Sophie S

Numerade Educator

Problem 1922

A student connect a moving coil voltmeter $\mathrm{V}$ and $\mathrm{Q}$ moving coil Ammeter $\mathrm{A}$ and resistor $\mathrm{R}$ as shown in figure? If the voltmeter reads 10 volt and the ammeter reads 2 Amp then $\mathrm{R}$ is(a) $=5 \Omega$
(b) $>5 \Omega$
(c) $<5 \Omega$
(d) $10 \Omega$

Narayan Hari

Numerade Educator

Problem 1923

The deflection in a Galvanometer falls from 50 division to 20 when $12 \Omega$ shunt is applied. The Galvanometer resistance is
(a) $18 \Omega$
(b) $36 \Omega$
(c) $24 \Omega$
(d) $30 \Omega$

Narayan Hari

Numerade Educator

Problem 1924

In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an ele. potential $\mathrm{V}$ and then made to describe semicircular paths of radius $\mathrm{r}$ using a magnetic field $\mathrm{B}$. If $\mathrm{V}$ and $\mathrm{B}$ are kept constant, the ratio [(Charge on the ion) / (mass of the ion)] will be proportional to.
(a) $\left(1 / r^{2}\right)$
(b) $r^{2}$
(c) $\mathrm{r}$
(d) $(1 / \mathrm{r})$

Supratim Pal

Numerade Educator

Problem 1925

A Galvanometer of resistance $15 \Omega$ is connected to a battery of 3 volt along with a resistance of $2950 \Omega$ in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
(a) $6050 \Omega$
(b) $4450 \Omega$
(c) $5050 \Omega$
(d) $5550 \Omega$

Supratim Pal

Numerade Educator

Problem 1926

A Galvanometer coil has a resistance of $15 \Omega$ and gives full scale deflection for a current of $4 \mathrm{~mA}$. To convert it to an ammeter of range 0 to $6 \mathrm{Amp}$
(a) $10 \mathrm{~m} \Omega$ resistance is to be connected in parallel to the galvanometer.
(b) $10 \mathrm{~m} \Omega$ resistance is to be connected in series with the galvanometer.
(c) $0.1 \Omega$ resistance is to be connected in parallel to the galvanometer.
(d) $0.1 \Omega$ resistance is to be connected in series with the galvanometer.

Narayan Hari

Numerade Educator

Problem 1927

The deflection in moving coil Galvanometer is reduced to half when it is shunted with a $40 \Omega$ coil. The resistance of the Galvanometer is
(c) $40 \Omega$
(a) $60 \Omega$
(b) $\overline{10 \Omega}$
(d) $20 \Omega$

Narayan Hari

Numerade Educator

Problem 1928

A straight rod of mass $\mathrm{m}$ and length $\mathrm{L}$ is suspended from the two identical springs as shown in figure. The spring is stretched a distance $\mathrm{y}_{0}$ due to the weight of the wire. The circuit has total resistance $\mathrm{R}$. when the magnetic field perpendicular to the plane of paper is switched on, springs are observed to extend further by the same distance $y_{0}$ the magnetic strength is

Saman Zulfiqar

Numerade Educator

Problem 1929

A conducting circular loop of radius a carries a constant
current I. It is placed in a uniform magnetic field $\mathrm{B}^{-}$, such
that $\mathrm{B}^{-}$ is perpendicular to the plane of the Loop. The magnetic force acting on the Loop is
(a) $\mathrm{B}^{-} \operatorname{Ir}$
(b) $\mathrm{B}^{-} \mathrm{I} \pi \mathrm{r}^{2}$
(c) Zero
(d) BI $(2 \pi \mathrm{r})$

Narayan Hari

Numerade Educator

Problem 1930

Two thin long parallel wires separated by a distance $\mathrm{y}$ are carrying a current I Amp each. The magnitude of the force per unit length exerted by one wire on other is
(a) $\left[\left(\mu_{0} I^{2}\right) / y^{2}\right]$
(b) $\left[\left(\mu_{o} I^{2}\right) /(2 \pi \mathrm{y})\right]$
(c) $\left[\left(\mu_{0}\right) /(2 \pi)\right](1 / y)$
(d) $\left[\left(\mu_{0}\right) /(2 \pi)\right]\left(1 / \mathrm{y}^{2}\right)$

Narayan Hari

Numerade Educator

Problem 1931

A closed Loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segment $\mathrm{PS}, \mathrm{SR}$ and $\mathrm{RQ}$ are $\mathrm{F}_{1}, \mathrm{~F}_{2}$ and $\mathrm{F}_{3}$ respectively and are in the plane of the paper and along the directions shown, the force on the segment $\mathrm{QP}$ is(b) $\mathrm{F}_{1}-\mathrm{F}_{2}+\mathrm{F}_{3}$
(c) $-\mathrm{F}_{1}+\mathrm{F}_{2}+\mathrm{F}_{3}$

Narayan Hari

Numerade Educator

Problem 1932

If two streams of protons move parallel to each other in the same direction, then they
(a) Do not exert any force on each other
(b) Repel each other
(c) Attract each other
(d) Get rotated to be perpendicular to each other.

Narayan Hari

Numerade Educator

Problem 1933

A coil in the shape of an equilateral triangle of side 115 suspended between the pole pieces of a permanent magnet such that $\mathrm{B}^{-}$ is in plane of the coil. If due to a current $\mathrm{I}$ in the triangle a torque $\tau$ acts on it, the side 1 of the triangle is
(a) $(2 / \sqrt{3})(\tau / \mathrm{BI})^{1 / 2}$
(b) $(2 / 3)(\tau / B I)$
(c) $2[\tau /\{\sqrt{(} 3) \mathrm{BI}\}]^{1 / 2}$
(d) $(1 / \sqrt{3})(\tau / \mathrm{BI})$

Ankur S

Numerade Educator

Problem 1934

In a moving coll galvanometer, the deflection of the $\operatorname{col} \theta 15$ related to ele. current I by the relation.
(a) $I \propto \tan \theta$
(b) $I \propto{\propto} \theta$
(c) $I \propto \theta^{2}$
(d) I $\propto \sqrt{\theta}$

Narayan Hari

Numerade Educator

Problem 1935

The unit of ele. current "AMPERE" is the current which when flowing through each of two parallel wires spaced 1 meter apart in vacuum and of infinite length will give rise to a force between them equal to $\mathrm{N} / \mathrm{m}$
(a) 1
(b) $2 \times 10^{-7}$
(c) $1 \times 10^{-2}$
(d) $4 \pi \times 10^{-7}$

Narayan Hari

Numerade Educator

Problem 1936

A Loop carrying current I lies in XY-plane as shown in the figure. The unit vector $\mathrm{k} \wedge$ is coming out of the plane of the paper. The magnetic moment of the current Loop is(a) $\mathrm{Ia}^{2} \mathrm{k} \wedge$
(b) $[(\pi / 2)+1] a^{2} I k \wedge$
(c) $-[(\pi / 2)+1] \mathrm{a}^{2} \mathrm{Ik} \wedge$
(d) $(2 \pi+1) a^{2} I k \wedge$

Supratim Pal

Numerade Educator

Problem 1937

A coil having N turns is wound tightly in the form of a spiral with inner and outer radii "a" and "b" respectively. When a current I passes through the coil, the magnetic field at the centre is
(a) $\left[\left(\mu_{0} \mathrm{NI}\right) / \mathrm{b}\right]$
(b) $\left[\left(2 \mu_{\circ} \mathrm{NI}\right) / \mathrm{a}\right]$
(c) $\left[\left(\mu_{0} \mathrm{NI}\right) /\{2(\mathrm{~b}-\mathrm{a})\}\right] \ln (\mathrm{ab})$
(d) $\left[\mu_{0} /\{2 \mathrm{NI}(\mathrm{b}-\mathrm{a})\}\right] \ln (\mathrm{ab})$

Narayan Hari

Numerade Educator

Problem 1938

A particle of mass $\mathrm{m}$ and charge q moves with a constant velocity v along the positive $\mathrm{x}$ -direction. It enters a region containing a uniform magnetic field B directed along the negative $z$ -direction, extending from $x=a$ to $x=b$. The minimum value of required so that the particle can just enter the region $\mathrm{x}>\mathrm{b}$ is
(a) $[(\mathrm{q} \mathrm{bB}) / \mathrm{m}]$
(b) $q(b-a)(B / m)$
(c) $[(\mathrm{qaB}) / \mathrm{m}]$
(d) $q(b+a)(B / 2 m)$

Narayan Hari

Numerade Educator

Problem 1939

An electron moving with a speed $y_{0}$ along the positive $x$ -axis
at $\mathrm{y}=0$ enters a region of uniform magnetic field $\mathrm{B}^{-}=-\mathrm{B}_{0} \mathrm{k} \wedge$ which exists to the right of y-axis. The electron exits from the region after some time with the speed at co-ordinate y then.

Prabhu Ramji

Numerade Educator

Problem 1940

A uniform conducting wire $\mathrm{ABC}$ has a mass 10 gram. $\mathrm{A}$ 12 Amp current is flowing through it. The wire is kept in uniform magnetic field $\vec{B}=2$ tesla the acceleration of the wire will be(a) zero
(b) $12 \mathrm{~m} / \mathrm{s}^{2}$ along $\mathrm{y}$ -axis
(c) $1.2 \times 10^{-3}\left(\mathrm{~m} / \mathrm{s}^{2}\right)$ along $\mathrm{y}$ -axis
(d) $0.6 \times 10^{-3}\left(\mathrm{~m} / \mathrm{s}^{2}\right)$ along $\mathrm{y}$ -axis

Narayan Hari

Numerade Educator

Problem 1941

The correct curve between the magnetic induction (B) along the axis of a long solenoid due to current flow 1 in it and distance $\mathrm{x}$ from one end is

Narayan Hari

Numerade Educator

Problem 1942

2. When any coil is placed in a uniform mag. field torque is acting on it. The graph of $\tau \rightarrow \theta$ is

Vishal Gupta

Numerade Educator

Problem 1943

A magnetic field $B^{-}=$ Bo $j \wedge$ exists in the region $a<x<2 a$ and $\mathrm{B}^{-}=-\mathrm{B}_{0} \mathrm{~J} \wedge$ in the region $2 \mathrm{a}<\mathrm{x}<3$ a where $\mathrm{B}_{0}$ is a
positive constant. A positive point charge moving with a velocity $\mathrm{V}^{-}=\mathrm{V}_{0} \uparrow$, where $\mathrm{V}_{0}$ is a positive constant, enters the magnetic field at $\mathrm{x}=\mathrm{a}$. The trajectory of the charge in this region can be like

Ankur S

Numerade Educator

Problem 1944

Graph of force per unit length between two long parallel current carrying conductors and the distance between them
(a) Straight line
(b) Parabola
(c) Ellipse
(d) Rectangular hyperbola

Narayan Hari

Numerade Educator

Problem 1945

An infinitely long hollow conducting cylinder with inner radius (R/2) and outer radius $\mathrm{R}$ carries a uniform current density
along its length. The magnitude of the magnetic field $\left|\mathrm{B}^{-}\right|$ as a function of the radial distance $\mathrm{r}$ from the axis is best represented by

Supratim Pal

Numerade Educator

Problem 1946

A charge $\mathrm{Q}$ is uniformly distributed over the surface of non-conducting disc of radius $\mathrm{R}$. The disc rotates about an axis perpendicular to its plane and passing through its centre with an angular velocity co. As a result of this rotation a magnetic field of induction $B$ is obtained at the centre of the disc. If we keep both the amount of charge placed on the disc and its angular velocity to be constant and vary the radius of the disc then the variation of the magnetic induction at the centre of the disc will be represented by the figure.

Rinku Devi

Numerade Educator

Problem 1947

For substances hysteresis B-H curves are given as shown in the figure. For making temporary magnet which of the following group is best.

Narayan Hari

Numerade Educator

Problem 1948

A curve between magnetic moment and temperature of magnetic is

Narayan Hari

Numerade Educator

Problem 1949

The variation of magnetic susceptibility ( $\mathrm{x}$ ) with temperature for a diamagnetic substance is best represented by

Narayan Hari

Numerade Educator

Problem 1950

The graph of magnetic susceptibility and magnetic field for paramagnetic substance is

Narayan Hari

Numerade Educator

Problem 1951

The variation of magnetic susceptibility ( $\mathrm{x}$ ) with absolute temperature $\mathrm{T}$ for a ferromagnetic material is given by.

Narayan Hari

Numerade Educator

Problem 1952

The variation of the intensity of magnetization (I) with respect to the magnetizing field $(\mathrm{H})$ in a diamagnetic substance is described by the graph

Narayan Hari

Numerade Educator

Problem 1953

The most appropriate magnetization $\mathrm{M} \rightarrow$ magnetizing field H curve for a paramagnetic substance is(a) $\mathrm{A}$
(b) B
(c) $\mathrm{C}$
(d) D

Narayan Hari

Numerade Educator

Problem 1954

An iron rod of length $L$ and magnetic moment $\mathrm{M}$ is bent in the form of a semicircle. Now its magnetic moment will be
(a) $\mathrm{M}$
(b) $(2 \mathrm{M} / \pi)$
(c) $(\mathrm{M} / \pi)$
(d) $\mathrm{M} \pi$

Nidhi Singhi

Numerade Educator

Problem 1955

Unit of magnetic Flux density is
(a) Tesla
(b) [(Weber) $/$ (meter) $\left.^{2}\right]$
(c) [(Newton) $/$ (Amp - meter)]
(d) All of the above

Mir Afzal

Numerade Educator

Problem 1956

Magnetic intensity for an axial point due to a short bar magnet of magnetic moment $\mathrm{M}$ is given by
(a) $\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$
(b) $\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{2}\right)$
(c) $\left(\mu_{0} / 2 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$
(d) $\left(\mu_{0} / 2 \pi\right)\left(\mathrm{M} / \mathrm{d}^{2}\right)$

Aja S

Numerade Educator

Problem 1957

A magnet of magnetic moment $\mathrm{M}$ and pole strength $\mathrm{m}$ is divided in two equal parts, then magnetic moment of each part will be
(a) $\mathrm{M}$
(b) $(\mathrm{M} / 2)$
(c) $(\mathrm{M} / 4)$
(d) $2 \mathrm{M}$

Hunza Gilgit

Numerade Educator

Problem 1958

If a magnet of pole strength $\mathrm{m}$ is divided into four parts such that the length and width of each part is half that of initial one, then the pole strength of each part will be
(a) $(\mathrm{m} / 4)$
(b) $(\mathrm{m} / 2)$
(c) $(\mathrm{m} / 8)$
(d) $4 \mathrm{~m}$

Hunza Gilgit

Numerade Educator

Problem 1959

The magnetism of magnet is due to
(a) The spin motion of electron
(b) Earth
(c) Pressure inside the earth core region
(d) Cosmic rays

Narayan Hari

Numerade Educator

Problem 1960

The magnetic field at a point $\mathrm{x}$ on the axis of a small bar magnet is equal to the at a point $\mathrm{y}$ on the equator of the same magnet. The ratio of the distances of $\mathrm{x}$ and $\mathrm{y}$ from the centre of the magnet is
(a) $2^{-3}$
(b) $2^{-(1 / 3)}$
(c) $2^{3}$
(d) $2^{+(1 / 3)}$

Hast Aggarwal

Numerade Educator

Problem 1961

The magnetic field due to a short magnet at a point on its axis at a distance $\mathrm{x} \mathrm{cm}$ from the middle point of the magnet is 200 gauss. The magnetic field at a point on the neutral axis at a distance $\mathrm{x} \mathrm{cm}$ from the middle of the magnet is gauss.
(a) 100
(b) 400
(c) 50
(d) 200

Eduard Sanchez

Numerade Educator

Problem 1962

A bar magnet having a magnetic moment of $2 \times 10^{4} \mathrm{JT}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $\mathrm{B}=6 \times 10^{-4}$ Tesla exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction $60^{\circ}$ from the field is
(a) $0.6 \mathrm{~J}$
(b) $12 \mathrm{~J}$
(c) $6 \mathrm{~J}$
(d) $2 \mathrm{~J}$

Hast Aggarwal

Numerade Educator

Problem 1963

A magnet of length $0.1 \mathrm{~m}$ and pole strength $10^{-4} \mathrm{~A} \mathrm{~m} .$ is kept in a magnetic field of 30 tesla at an angle of 300 . The Torque acting on it is $\times 10^{-4}$ Joule.
(a) $7.5$
(b) 3
(c) $1.5$
(d) 6

Hast Aggarwal

Numerade Educator

Problem 1964

In the case of bar magnet, lines of magnetic induction
(a) Start from the North pole and end at the South pole
(b) Run continuously through the bar and outside
(c) Emerge in circular paths from the middle of the bar
(d) Are produced only at the North pole like rays of light from
a bulb.

Narayan Hari

Numerade Educator

Problem 1965

A small bar magnet of moment $\mathrm{M}$ is placed in a uniform field of $\mathrm{H}$. If magnet makes an angle of $30^{\circ}$ with field, the torque acting on the magnet is
(a) $\mathrm{MH}$
(b) $(\mathrm{MH} / 2)$
(c) $(\mathrm{MH} / 3)$
(d) $(\mathrm{MH} / 4)$

Narayan Hari

Numerade Educator

Problem 1966

The effective length of a magnet is $31.4 \mathrm{~cm}$ and its pole strength is $0.5 \mathrm{~A} \mathrm{~m}$. The magnetic moment, if it is bent in the form of a semicircle will be Amp.m $^{2}$
(a) $0.1$
(b) $0.01$
(c) $0.2$
(d) $1.2$

Narayan Hari

Numerade Educator

Problem 1967

$\mathrm{A}$ bar magnet of length $10 \mathrm{~cm}$ and having the pole strength equal $10^{3} \mathrm{Am}$ to is kept in a magnetic field having magnetic induction (B) equal to $4 \pi \times 10^{3}$ tesla. It makes an angle of $30^{\circ}$ with the direction of magnetic induction. The value of the torque acting on the magnet is

Joule.
(a) $2 \pi \times 10^{-7}$
(b) $2 \pi \times 10^{5}$
(c) $0.5$
(d) $0.5 \times 10^{2}$

Hast Aggarwal

Numerade Educator

Problem 1968

A small bar magnet has a magnetic moment $1.2 \mathrm{~A} \cdot \mathrm{m}^{2}$. The magnetic field at a distance $0.1 \mathrm{~m}$ on its axis will be tesla.
(a) $1.2 \times 10^{-4}$
(b) $2.4 \times 10^{-4}$
(c) $2.4 \times 10^{4}$
(d) $1.2 \times 10^{4}$

Narayan Hari

Numerade Educator

Problem 1969

Force between two identical bar magnets whose centers are I meter apart is $4.8 \mathrm{~N}$, when their axes are in the same line. If separation is increased to $2 r$, the force between them is reduced to
(a) $2.4 \mathrm{~N}$
(b) $1.2 \mathrm{~N}$
(c) $0.6 \mathrm{~N}$
(d) $0.3 \mathrm{~N}$

Hast Aggarwal

Numerade Educator

Problem 1970

Two equal bar magnets are kept as shown in the figure. The direction of resultant mag. field indicated by arrow head at the point $P$ is approximately

Raj Bala

Numerade Educator

Problem 1971

Two equal bar magnets are kept as shown in the figure. The direction of resultant mag. field indicated by arrow head at the point $P$ is approximately

Raj Bala

Numerade Educator

Problem 1972

A magnet of magnetic moment $50 \uparrow \mathrm{A} \mathrm{m}^{2}$ is placed along the $\mathrm{X}$ -axis in a mag. field $\mathrm{B}^{-}=(0.5 \uparrow+3.0 \mathrm{~J} \wedge$ ) Tesla. The torque acting on the magnet is
N.m.
(c) $75 \mathrm{k} \wedge$
(d) $25 \sqrt{5} \mathrm{k} \wedge$
(a) $175 \mathrm{k}$
(b) $150 \mathrm{k}$

Narayan Hari

Numerade Educator

Problem 1973

A bar magnet is $10 \mathrm{~cm}$ long and is kept with its North (N) pole pointing North. A neutral point is formed at a distance of $15 \mathrm{~cm}$ from each pole. Given the horizontal component of earth's field to be $0.4$ Gauss. The pole strength of the magnet is
A.m.
(a) 9
(b) $6.75$
(c) 27
(d) $13.5$

Narayan Hari

Numerade Educator

Problem 1974

The true value of angle of dip at a place is $60^{\circ}$, the apparent dip in a plane inclined at an angle of $30^{\circ}$ with magnetic meridian is.
(a) $\tan ^{-1}(1 / 2)$
(b) $\tan ^{-1} 2$
(c) $\tan ^{-1}(2 / 3)$
(d) None of these

Ajay Singhal

Numerade Educator

Problem 1975

A dip needle lies initially in the magnetic meridian when it shows an angle of dip at a place. The dip circle is rotted through an angle $\mathrm{x}$ in the horizontal plane and then it shows an angle of dip $\theta^{\prime}$. Then $\left[\left(\tan \theta^{\prime}\right) /(\tan \theta)\right]$ is
(a) $[1 /(\cos x)]$
(b) $[1 /(\sin x)]$
(c) $[1 /(\tan \mathrm{x})]$
(d) $\cos \mathrm{x}$

Narayan Hari

Numerade Educator

Problem 1976

A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be $2 \mathrm{sec}$. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be $2 \mathrm{sec}$. Then the angle of dip is
(a) $0^{\circ}$
(b) $30^{\circ}$
(c) $45^{\circ}$
(d) $90^{\circ}$

Hast Aggarwal

Numerade Educator

Problem 1977

Two iclentical short bar magnets, each having magnetic moment $\mathrm{M}$ are placed a distance of $2 \mathrm{~d}$ apart with axes perpendicular to each other in a horizontal plane. The magnetic induction at a point midway between them is.
(a) $\sqrt{2}\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$
(b) $\sqrt{3}\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$
(c) $\sqrt{4}\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$
(d) $\sqrt{5}\left(\mu_{0} / 4 \pi\right)\left(\mathrm{M} / \mathrm{d}^{3}\right)$

Aja S

Numerade Educator

Problem 1978

The magnetic susceptibility of a paramagnetic substance at $73^{\circ} \mathrm{C}$ is $0.0060$, then its value at $-173^{\circ} \mathrm{C}$ will be
(a) $0.0030$
(b) $0.0120$
(c) $0.0180$
(d) $0.0045$

Narayan Hari

Numerade Educator

Problem 1979

Needles $\mathrm{N}_{1}, \mathrm{~N}_{2}$ and $\mathrm{N}_{3}$ are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet when brought close to them will
(a) Attract $\mathrm{N}_{1}$ strongly, $\mathrm{N}_{2}$ weakly and repel $\mathrm{N}_{3}$ weakly
(b) Attract $\mathrm{N}_{1}$ strongly, but repel $\mathrm{N}_{2}$ and $\mathrm{N}_{3}$ weakly
(c) Attract all three of them
(d) Attract $\mathrm{N}_{1}$ and $\mathrm{N}_{2}$ strongly but repel $\mathrm{N}_{2}$

Aja S

Numerade Educator

Problem 1980

Two identical bar magnets with a length $10 \mathrm{~cm}$ and weight $50 \mathrm{gm}$ weight are arranged freely with their like pole facing in a inverted vertical glass tube. The upper magnet hangs in the between the nearest pole of the magnet is $3 \mathrm{~mm}$. Pole strength of the poles of earth magnet will be Amp. meter

Ankur S

Numerade Educator

Problem 1981

Susceptibility of one material at $300 \mathrm{k}$ is $1.2 \times 10^{-2}$. The temperature at which susceptibility will be $1.8 \times 10^{-5}$ is kelvin.
(a) 450
(b) 200
(c) 375
(d) None

Ajay Singhal

Numerade Educator

Problem 1982

Due to a small magnet, intensity at a distance $\mathrm{x}$ in the end on position is 9 Gauss. what will be the intensity at a distance $(\mathrm{x} / 2)$ on broad side on position.
(a) 9 Gauss
(b) 4 Gauss
(c) 36 Gauss
(d) 4.5 Gauss A domain in a ferromagnetic s1hh

Stephen Zaffke

Numerade Educator

Problem 1983

A domain in a ferromagnetic substance is in the form of a cube of side length $1 \mu \mathrm{m}$. If it contains $8 \times 10^{10}$ atoms and each atomic dipole has a dipole moment of $9 \times 10^{-24} \mathrm{~A} \mathrm{~m}^{2}$ then magnetization of the domain is $\mathrm{A} \mathrm{m}^{-1}$
a) $7.2 \times 10^{5}$
(b) $7.2 \times 10^{3}$
(c) $7.2 \times 10^{5}$
(d) $7.2 \times 10^{3}$

Khoobchandra Agrawal

Khoobchandra Agrawal

Numerade Educator

Problem 1984

The magnetic susceptibility is negative for
(a) Paramagnetic materials
(b) Diamagnetic materials
(c) Ferromagnetic materials
(d) Paramagnetic and ferromagnetic materials

Aja S

Numerade Educator

Problem 1985

When 2 Amp current is passed through a tangent galvanometer. It gives a deflection of $30^{\circ} .$ For $60^{\circ}$ deflection, the current must be
(a) $1 \mathrm{Amp}$
(b) $2 \sqrt{3 a m p}$
(c) $4 \mathrm{amp}$
(d) $6 \mathrm{Amp}$

Vysakh M

Numerade Educator

Problem 1986

The time period of a freely suspended magnet is a
4 seconds. If it is broken in length into two equal parts and one part is suspended in the same way, then its time period will be
(a) $4 \mathrm{sec}$
(b) $2 \mathrm{sec}$
(c) $0.5 \mathrm{sec}$
(d) $0.25 \mathrm{sec}$

Hunza Gilgit

Numerade Educator

Problem 1987

A thin magnetic needle oscillates in a horizontal plane with a period $\mathrm{T}$. It is broken into n equal parts. The time period of each part will be
(a) $\mathrm{T}$
(b) $\mathrm{n}^{2} \mathrm{~T}$
(c) $(\mathrm{T} / \mathrm{n})$
(d) $\left(\mathrm{T} / \mathrm{n}^{2}\right)$

Hast Aggarwal

Numerade Educator

Problem 1988

A thin magnetic needle oscillates in a horizontal plane with a period $\mathrm{T}$. It is broken into n equal parts. The time period of each part will be
(a) $\mathrm{T}$
(b) $\mathrm{n}^{2} \mathrm{~T}$
(c) $(\mathrm{T} / \mathrm{n})$
(d) $\left(\mathrm{T} / \mathrm{n}^{2}\right)$

Hast Aggarwal

Numerade Educator

Problem 1989

The coercively of a bar magnet is $100 \mathrm{~A} / \mathrm{m}$. It is to be diamagnetism by placing it inside a solenoid of length $100 \mathrm{~cm}$ and number of turns 50 . The current flowing through the solenoid will be
(a) $4 \mathrm{~A}$
(b) $2 \mathrm{~A}$
(c) $1 \mathrm{~A}$
(d) Zero

Narayan Hari

Numerade Educator

Problem 1990

The angles of dip at two places are $30^{\circ}$ and $45^{\circ}$. The ratio of horizontal components of earth's magnetic field at the two places will be
(a) $\sqrt{3}: \sqrt{2}$
(b) $1: \sqrt{2}$
(c) $1: 2$
(d) $1: \sqrt{3}$

Ajay Singhal

Numerade Educator

Problem 1991

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: We cannot think of magnetic field configuration with three poles. Reason : A bar magnet does exert a torque on itself due to its own field.

Narayan Hari

Numerade Educator

Problem 1992

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: If a compass needle be kept at magnetic north pole of the earth, the compass needle may stay in any direction. Reason: Dip needle will stay vertical at the north pole.

Hast Aggarwal

Numerade Educator

Problem 1993

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: Diamagnetic materials can exhibit magnetism. Reason: Diamagnetic materials have permanent magnetic dipole moment.

Narayan Hari

Numerade Educator

Problem 1994

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: A paramagnetic sample displays greater magnetization when it is cooled. Reason: The magnetization does not depend on temperature.

Khoobchandra Agrawal

Khoobchandra Agrawal

Numerade Educator

Problem 1995

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: Two short magnets are placed on a cork which floats on water. The magnets are placed such that the axis of one bisects the axis of other at right angles. Then the cork has neither translational nor rotational motion. Reason: Net force on the cork is zero.

Hast Aggarwal

Numerade Educator

Problem 1996

Read the assertion and reason caretully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: Cyclotron does not accelerate electron. Reason: Mass of the electron is very small.

Narayan Hari

Numerade Educator

Problem 1997

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: Cyclotron is a device which is used to accelerate the positive ion. Reason: Cyclotron frequency depends upon the velocity.

Narayan Hari

Numerade Educator

Problem 1998

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: The magnetic field produced by a current carrying solenoid is independent of its length and cross-sectional area Reason: The magnetic field inside the solenoid is uniform.

Narayan Hari

Numerade Educator

Problem 1999

Read the assertion and reason carefully to mark the correct option out of the options given below.
(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion,
(C) If assertion is true but reason is false.
(D) If the assertion and reason both the false.
(E) If assertion is false but reason is true.
Assertion: Torque on the coil is the maximum, when coil is suspended in a radial magnetic field. Reason: The torque tends to rotate the coil on its own axis.

Narayan Hari

Numerade Educator

Problem 2000

Advanced countries are making use of powerful electro magnets to move trains at very high speed. These trains are called maglev trains. These trains float on a guideway and do not run on steel tail trucks. Instead of using an engine based on fissile fuels, they make use of magnetic field forces. The magnetized coil are arranged in the guideway which repel the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technique called electrodynamics suspension. When current passes in the coils guideway, a typical magnetic field is set up between the under carriage of train and guideway which pushes and pulls the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to move at very high speed.
The force which makes mangle move is
(a) Gravitational
(b) Magnetic
(c) Nuclear force
(d) Air drag

Khaled Yasein

Numerade Educator

Problem 2001

Advanced countries are making use of powerful electro magnets to move trains at very high speed. These trains are called maglev trains. These trains float on a guideway and do not run on steel tail trucks. Instead of using an engine based on fissile fuels, they make use of magnetic field forces. The magnetized coil are arranged in the guideway which repel the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technique called electrodynamics suspension. When current passes in the coils guideway, a typical magnetic field is set up between the under carriage of train and guideway which pushes and pulls the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to move at very high speed.
The disadvantage of magtev train is
(a) More friction
(b) Less pollution
(c) Less wear and tear
(d) High initial cost

Khaled Yasein

Numerade Educator

Problem 2002

Advanced countries are making use of powerful electro magnets to move trains at very high speed. These trains are called maglev trains. These trains float on a guideway and do not run on steel tail trucks. Instead of using an engine based on fissile fuels, they make use of magnetic field forces. The magnetized coil are arranged in the guideway which repel the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technique called electrodynamics suspension. When current passes in the coils guideway, a typical magnetic field is set up between the under carriage of train and guideway which pushes and pulls the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to move at very high speed.
The levitation of the train is due to
(a) Mechanical tone
(b) Electros static attraction
(c) Electrostatic repulsion
(d) Magnetic repulsion

Khaled Yasein

Numerade Educator

Problem 2003

A current Loop $\mathrm{ABCD}$ is held fixed on the plane of the paper as shown in the figure. The arcs $B C$ (radius $=b$ ) and $D A$ (radius $=\mathrm{a}$ ) of the Loop are joined by two straight wires $\mathrm{AB}$ and $\mathrm{CD}$. A steady current $\mathrm{I}$ is flowing in the Loop. angle made by $\mathrm{AB}$ and $\mathrm{CD}$ at the origin is $30^{\circ}$. Another straight thin wire with steady current $\mathrm{I}_{1}$ flowing out of the plane of the paper is kept at the origin.

The magnitude of the magnetic field (B) due to the Loop $\mathrm{ABCD}$ at the origin $(0)$ is(A) zero
(b) $\left[\left\{\mu_{0} I(b-a)\right\} /(24 a b)\right]$
(c) $\left[\left\{\mu_{0} I(b-a)\right\} /(4 \pi a b)\right]$
(d) $\left[\left(\mu_{0} I\right) /(4 \pi)\right][2(b-a)+(\pi / 3)(a+b)]$

Jordan Vanevery

Jordan Vanevery

Numerade Educator

Problem 2004

A current Loop $A B C D$ is held fixed on the plane of the paper as shown in the figure. The arcs $\mathrm{BC}$ (radius $=\mathrm{b}$ ) and $\mathrm{DA}$ (radius $=\mathrm{a}$ ) of the Loop are joined by two straight wires $\mathrm{AB}$ and CD. A steady current $I$ is flowing in the Loop. angle made by $\mathrm{AB}$ and $\mathrm{CD}$ at the origin is $30^{\circ}$. Another straight thin wire with steady current $\mathrm{I}_{1}$ flowing out of the plane of the paper is kept at the origin.
Due to the presence of the current $\mathrm{I}_{1}$ at the origin
(a) The forces on $\mathrm{AB}$ and $\mathrm{DC}$ are zero.
(b) The forces on $A D$ and $B C$ are zero.
(c) The magnitude of the net force on the loop is given by $\left[\left(\mu_{0} I I_{1}\right) /(4 \pi)\right][2(b-a)+(\pi / 3)(a+b)]$
(d) The magnitude of the net force on the loop is given by $\left[\left(\mu_{0} I \bar{I}_{1}\right) /(24 \mathrm{ab})\right](\mathrm{b}-\mathrm{a})$

Jordan Vanevery

Jordan Vanevery

Numerade Educator

Problem 2005

In each of the following questions, Match column-I and column-II and select the correct match out of the four given choices.\begin{tabular}{l|l}
Column - I & Column - II
\end{tabular}
(A) Biot-savart's law
(P) Direction of magnetic field induction
(B) Right hand thumb rule
(Q) Magnitude of magnetic field induction
(C) Fleming's left hand rule
(R) Direction of induced current
(D) Fleming's right hand rule
(S) Direction of force due to a mag. field
(a) $\mathrm{A} \rightarrow \mathrm{Q} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{R} ; \mathrm{D} \rightarrow \mathrm{S}$
(b) $\mathrm{A} \rightarrow \mathrm{Q} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{R}$
(c) $\mathrm{A} \rightarrow \mathrm{P} ; \mathrm{B} \rightarrow \mathrm{Q} ; \mathrm{C} \rightarrow \mathrm{R} ; \mathrm{D} \rightarrow \mathrm{S}$
(d) $\mathrm{A} \rightarrow \mathrm{P}: \mathrm{B} \rightarrow \mathrm{Q}: \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{R}$

Vishal Gupta

Numerade Educator

Problem 2006

In each of the following questions, Match column-I and column-II and select the correct match out of the four given choices.\begin{tabular}{l|r}
Column-I & Column - II
\end{tabular}
(A) Magnetic field induction due to Current 1 through straight conductor at a perpendicular distance $\mathrm{r}$.
(B) Magnetic field induction at
(Q) $\left[\left(\mu_{0} \mathrm{I}\right) /(4 \pi \mathrm{r})\right]$
the centre of current $(1)$ carrying Loop of radius (r)
(C) Magnetic field induction at the
(R) $\left[\mu_{0} /(4 \pi)\right](2 \mathrm{I} / \mathrm{r})$
axis of current (1) carrying coil of radius (r) at a distance (r) from centre of coil
(D) Magnetic field induction at the
(S) $\left[\mu_{0} /(4 \sqrt{2})\right](\mathrm{L} / \mathrm{r})$
at the centre due to circular arc of length $\mathrm{r}$ and radius (r) carrying current (I)
(a) $\mathrm{A} \rightarrow \mathrm{R} ; \mathrm{B} \rightarrow \mathrm{S} ; \mathrm{C} \rightarrow \mathrm{P} ; \mathrm{D} \rightarrow \mathrm{Q}$
(b) $\mathrm{A} \rightarrow \mathrm{R} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{Q}$
(c) $\mathrm{A} \rightarrow \mathrm{P} ; \mathrm{B} \rightarrow \mathrm{Q} ; \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{R}$
(d) $\mathrm{A} \rightarrow \mathrm{Q} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{R} ; \mathrm{D} \rightarrow \mathrm{S}$

Bettina Hanlon

Numerade Educator

Problem 2007

In each of the following questions, Match column-I and column-II and select the correct match out of the four given choices.(B) Ammeter
(Q) Moderate resistance
(C) Voltmeter
(R) High, Low or moderate resistance
(D) Avometer
(S) High resistance
(a) $\mathrm{A} \rightarrow \mathrm{P} ; \mathrm{B} \rightarrow \mathrm{Q} ; \mathrm{C} \rightarrow \mathrm{R} ; \mathrm{D} \rightarrow \mathrm{S}$
(b) $\mathrm{A} \rightarrow \mathrm{P} ; \mathrm{B} \rightarrow \mathrm{Q} ; \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{R}$
(c) $\mathrm{A} \rightarrow \mathrm{Q} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{R} ; \mathrm{D} \rightarrow \mathrm{S}$
(d) $\mathrm{A} \rightarrow \mathrm{Q} ; \mathrm{B} \rightarrow \mathrm{P} ; \mathrm{C} \rightarrow \mathrm{S} ; \mathrm{D} \rightarrow \mathrm{R}$

Prem Bijarniya

Numerade Educator

Problem 2008

In this section each equation has some statements
$(\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D} \ldots \ldots . .)$ given in column-I and some statements
$(\mathrm{P}, \mathrm{Q}, \mathrm{R}, \mathrm{S}, \mathrm{T}, \ldots \ldots)$ in column-II. Any given statement in
column-I can have correct matching with ONE OR MORE statements (s) in column-II.

Two wires each carrying a steady current-I are shown in four configurations in column-I. Some of the resulting effects are described in column-II. Match the statements in column-I with the statements in column-II.

Amita Prajapat

Numerade Educator

Problem 2009

In this section each equation has some statements
$(A, B, C, D \ldots \ldots)$ given in column-I and some statements
$(\mathrm{P}, \mathrm{Q}, \mathrm{R}, \mathrm{S}, \mathrm{T}, \ldots \ldots)$ in column-II. Any given statement in
column-I can have correct matching with ONE OR MORE statements (s) in column-II.
The physical quantities are given in column-I and their various related factors in column-II.\begin{tabular}{l|l}
Column-I & $\underline{\text { Column-II }}$ \\
\hline
\end{tabular}
(A) Torque on a coil carrying current when
(P) Restoring torque per unit twist of the
(B) current sensitivity of galvanometer
(Q) Number of turns in the coil(N)
(C) Voltage sensitivity of galvanometer
(R) Magnetic field (B)
(D) figure of merit of galvanometer
(S) Area of the coil $(\mathrm{A})$

Amit Srivastava

Amit Srivastava

Numerade Educator

Problem 2010

In this section each equation has some statements $(\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D} \ldots \ldots . .)$ given in column-I and some statements
$(\mathrm{P}, \mathrm{Q}, \mathrm{R}, \mathrm{S}, \mathrm{T}, \ldots \ldots)$ in column-II. Any given statement in
column-I can have correct matching with ONE OR MORE statements (s) in column-II.\begin{tabular}{l|r} Column-I & Column-II \\ \hline \end{tabular}
(A) A charged particle moving
(P) un deflected parallel to direction of mag. field
(B) A charged particle moving
(Q) circular path perpendicular to the direction of magnetic field
(C) A charged particle moving
(R) Helical path at an angle in a region of strong mag. field
(D) A charged particle moving
(S) parabolic path in a strong and uniform electric field of large region

Suzanne W.

Numerade Educator