NEET Magnetism and Matter — Set 2

Question 1

A material with $ \mu_r = 600 $ and $ H = 300 \, \text{A m}^{-1} $ has $ B $: (Take $ \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} $).

Accepted Answer

$ B = \mu_0 \mu_r H $. Given: $ \mu_r = 600 $, $ H = 300 \, \text{A m}^{-1} $, $ \mu_0 = 4\pi \times 10^{-7} $. $ B = 4\pi \times 10^{-7} \times 600 \times 300 = 0.22608 \, \text{T} \approx 0.23 \, \text{T} $.

Question 2

A bar magnet’s field resembles that of a solenoid because:

Accepted Answer

A bar magnet’s magnetic field mimics that of a solenoid due to the analogy that its magnetization can be modeled as arising from circulating currents within the material, similar to the current loops in a solenoid, producing comparable field patterns with north and south poles.

Question 3

The net magnetic flux through a closed surface surrounding a bar magnet is:

Accepted Answer

Gauss’s law for magnetism states that the net magnetic flux through any closed surface is zero, as magnetic field lines form closed loops with no monopoles.

NEET Physics: Magnetism and Matter — Practice Set 2

Q1. A material with \( \mu_r = 600 \) and \( H = 300 \, \text{A m}^{-1} \) has \( B \): (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).

Q2. A bar magnet’s field resembles that of a solenoid because:

Q3. The net magnetic flux through a closed surface surrounding a bar magnet is:

Q4. A material that exhibits strong magnetism due to the growth and alignment of microscopic domains when placed in an external field is:

Q5. A material that conducts electricity perfectly while expelling magnetic fields relies on:

Q6. The magnetic potential energy of a dipole with \( m = 0.6 \, \text{A m}^2 \) in a field \( B = 0.3 \, \text{T} \) at \( 60^\circ \) is:

Q7. A material has \( B = 0.54 \, \text{T} \) and \( M = 4.0 \times 10^5 \, \text{A m}^{-1} \). What is \( H \)? (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).

Q8. The magnetic field contribution \( B_m \) due to a material with \( M = 3 \times 10^5 \, \text{A m}^{-1} \) is: (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).

Q9. A material that conducts electricity perfectly and repels magnetic fields is likely operating as:

Q10. A bar magnet with magnetic moment \( 2.0 \, \text{A m}^2 \) is placed at a distance of \( 0.2 \, \text{m} \) along its axis. What is the magnetic field \( B \) at that point? (Take \( \mu_0 = 4\pi \times 10^{-7} \, \text{T m A}^{-1} \)).