Chapter Questions
State the expression for magnetic induction field on axial and equatorial line. Give its direction.
Define retentivity.
What is meant by an electromagnetic induction?
State Fleming's right hand rule.
Define a neutral point. Give the location of neutral points. When the North Pole of a bar magnet faces geographic north and geographic south.
Give the relation between V, N and I with respect to the primary and secondary coils of a transformer.
State Lenz's law.
Explain the principle of an electric generator.
Define: (1) magnetic field (2) magnetic lines of force
Define intensity of magnetisation magnetic susceptibility and retentivity. Give their SI units.
Which observation made in Oersted's experiment with a current carrying conductor concludes that the magnetic induction is proportional to the strength of the current in the conductor?
What is the difference between an $\mathrm{AC}$ dynamo and a DC dynamo?
What is magnetic saturation?
Define dia, para and ferromagnetic substances. Give examples.
Why the magnetic lines of force away from a straight conductor carrying current are elliptical?
Define(a) inductance(b) self induction(c) mutual induction
Define the pole strength of a magnet. What is the S.I. unit of pole strength?
What is a domain in ferromagnetic substances?
What type of magnetic field is observed at the centre of a circular coil carrying current?
Give the principle of a transformer? State the types of transformer
What is meant by electromagnetism?
Why is Ewing's theory called molecular theory of magnetism?
What is meant by a solenoid?
Why do magnetic lines of force pass through iron more freely than through air?
According to Ewing's molecular theory, why is steel used to make permanent magnets?
Which rule is used to find the force on a current carrying wire placed in a magnetic field?
Mention the energy conversions taking place in loud speaker and microphone.
Define magnetic induction field $\mathrm{B}$. Intensity of magnetic field $(\mathrm{H})$ and state their unit.
What happens to the length of a iron bar when it is magnetised?
State the principle of a moving coil galvanometer?
State the properties of(a) diamagnetic(b) paramagnetic(c) ferromagnetic substance
Explain how will you calculate magnetic moment (M) of a bar magnet using neutral points?
Explain domain theory.
Give the properties of a solenoid.
Calculate magnetic field induction $\mathrm{B}$ due to a conductor carrying current $5 \mathrm{~A}$ at a distance of $10 \mathrm{~cm}$ from it.
Write a note on important magnetic properties?
Give various characteristics of magnetic lines of force.
Describe Ewing molecular theory.
Calculate magnetic field induction ' $B$ ' at the centre of a circular coil having 500 turns, radius $\pi \mathrm{cm}$ and carrying $5 \mathrm{~A}$ of current,
Explain Oersted's experiment.
Explain why isolated magnetic poles do not exist?
What is modern electron theory?
Explain Faraday's experiment using a magnet and a coil and state Faraday's laws of electromagnetism
Explain magnetic induction ' $B$ ' and intensity of magnetizing field.
Distinguish between absolute and relative permeability of a medium.
Describe moving coil galvanometer.
Explain in detail:(a) Electric motor(b) $\mathrm{AC}$ generator(c) DC generator(d) Transformer
Write a note on terrestrial magnetism.
Write a note on: (1) self-inductance (2) mutual inductance
How do you locate the neutral points when(1) the North Pole of a bar magnet faces geographical north and(2) when the south pole of bar magnet faces geographical north?