The coercivity of a small magnet where the ferromagnet gets...

The coercivity of a small magnet where the ferromagnet gets demagnetized is $3 \times 10^{3} \mathrm{~A} \mathrm{~m}^{-1}$. The current required to be passed in a solenoid of length $10 \mathrm{~cm}$ and number of turns 100 , so that the magnet gets demagnetized when inside the solenoid is [2014] (A) $30 \mathrm{~mA}$ (B) $60 \mathrm{~mA}$ (C) $3 \mathrm{~A}$ (D) $6 \mathrm{~A}$

The coercivity of a small magnet where the ferromagnet gets demagnetized is $3 \times 10^{3} \mathrm{~A} \mathrm{~m}^{-1}$. The current required to be passed in a solenoid of length $10 \mathrm{~cm}$ and number of turns 100 , so that the magnet gets demagnetized when inside the solenoid is [2014]
(A) $30 \mathrm{~mA}$
(B) $60 \mathrm{~mA}$
(C) $3 \mathrm{~A}$
(D) $6 \mathrm{~A}$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Coercivity

Coercivity is a property of ferromagnetic materials that quantifies the strength of the reverse magnetic field required to bring the net magnetization of the material to zero. It is a measure of a material's resistance to becoming demagnetized and is crucial for applications where the stability of magnetic states is important.

Solenoid

A solenoid is a cylindrical coil of wire acting as a magnet when carrying electric current. It creates a nearly uniform magnetic field within its interior, and its design parameters — such as the number of turns, length, and current flowing through it — determine the strength of the magnetic field generated.

Magnetic Field in a Solenoid (Ampère's Law)

The magnetic field inside a solenoid is governed by Ampère's Law, which relates the magnetic field to the current and coil geometry. In an ideal solenoid, the field is given by H = nI, where n is the number of turns per unit length and I is the current. This relationship is essential in determining the required current to achieve a specific magnetic field strength, such as the field needed to demagnetize a material with a known coercivity.

Transcript

Please give Ace some feedback