NEET Magnetism and Matter — Set 6

Question 1

A paramagnetic material with $ \chi = 1.5 \times 10^{-3} $ in $ H = 600 \, \text{A m}^{-1} $ has magnetization $ M $:

Accepted Answer

$ M = \chi H $. Given: $ \chi = 1.5 \times 10^{-3} $, $ H = 600 \, \text{A m}^{-1} $. $ M = 1.5 \times 10^{-3} \times 600 = 0.9 \, \text{A m}^{-1} $.

Question 2

The magnetic field inside a material increases significantly when placed in an external field due to:

Accepted Answer

In ferromagnetic materials, the magnetic field inside increases significantly because the external field aligns and expands pre-existing magnetic domains, enhancing the overall magnetization and field strength far beyond the applied field.

Question 3

What is the magnetic field at a point on the equatorial line of a bar magnet with magnetic moment $ 2 \, \text{A m}^2 $ at a distance of $ 10 \, \text{cm} $ from its center? (Take $ \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} $).

Accepted Answer

The magnetic field on the equatorial line is $ B = \frac{\mu_0}{4\pi} \frac{m}{r^3} $. Given: $ m = 2 \, \text{A m}^2 $, $ r = 0.1 \, \text{m} $, $ \frac{\mu_0}{4\pi} = 10^{-7} \, \text{T m A}^{-1} $. Substitute: $ B = 10^{-7} \times \frac{2}{(0.1)^3} = 10^{-7} \times \frac{2}{0.001} = 2 \times 10^{-4} \, \text{T} $.

NEET Physics: Magnetism and Matter — Practice Set 6

Q1. A paramagnetic material with \( \chi = 1.5 \times 10^{-3} \) in \( H = 600 \, \text{A m}^{-1} \) has magnetization \( M \):

Q2. The magnetic field inside a material increases significantly when placed in an external field due to:

Q3. What is the magnetic field at a point on the equatorial line of a bar magnet with magnetic moment \( 2 \, \text{A m}^2 \) at a distance of \( 10 \, \text{cm} \) from its center? (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).

Q4. A material with susceptibility \( \chi = 4 \times 10^{-3} \) has a relative permeability \( \mu_r \) of:

Q5. The magnetic field inside a long solenoid is uniform because:

Q6. A magnetic dipole of moment \( 0.2 \, \text{A m}^2 \) is placed in a uniform field of \( 0.3 \, \text{T} \) at \( 45^\circ \). What is the torque on the dipole?

Q7. A paramagnetic material with \( \chi = 7 \times 10^{-4} \) in \( H = 3000 \, \text{A m}^{-1} \) has magnetization \( M \):

Q8. A material’s weak attraction to a magnetic field is due to:

Q9. The reason a bar magnet cannot exert a torque on itself is:

Q10. A material has \( B = 0.65 \, \text{T} \) and \( M = 4.5 \times 10^5 \, \text{A m}^{-1} \). What is \( H \)? (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).