Question

A perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field $\overrightarrow{\mathrm{B}}$. Then the field inside the paramagnetic substance is:

JEE Main 2020 (03 Sep Shift 2)

Options

• A: $\overrightarrow{\mathrm{B}}$
• B: Zero
• C: much large than $\left|\overrightarrow{\mathrm{B}}\right|$ and parallel to $\overrightarrow{\mathrm{B}}$
• D: much large than $\left|\overrightarrow{\mathrm{B}}\right|$ but opposite to $\overrightarrow{\mathrm{B}}$

Question

Following plots show Magnetization $\left(M\right)$ vs Magnetising field $\left(H\right)$ and Magnetic susceptibility $\left(\mathrm{\chi }\right)$ vs Temperature $\left(T\right)$ graph :

Which of the following combination will be represented by a diamagnetic material?

JEE Main 2021 (01 Sep Shift 2)

Options

• A: $\left(\mathrm{b}\right), \left(\mathrm{c}\right)$
• B: $\left(\mathrm{b}\right), \left(\mathrm{d}\right)$
• C: $\left(\mathrm{a}\right), \left(\mathrm{d}\right)$
• D: $\left(\mathrm{a}\right), \left(\mathrm{c}\right)$

Question

Which of the following statements are correct?
(A) Electric monopoles do not exist whereas magnetic monopoles exist.
(B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
(C) Magnetic field lines are completely confined within a toroid.
(D) Magnetic field lines inside a bar magnet are not parallel.
(E) $\chi =-1$ is the condition for a perfect diamagnetic material, where $\chi$ is its magnetic susceptibility.

Choose the correct answer from the options given below :

JEE Main 2021 (18 Mar Shift 2)

Options

• A: (C) and (E) only
• B: (B) and (D) only
• C: (A) and (B) only
• D: (B) and (C) only

Question

An electron with energy $0.1\mathrm{keV}$ moves at right angle to the earth's magnetic field of $1\times {10}^{-4}{\mathrm{Wbm}}^{-2}$. The frequency of revolution of the electron will be
(Take mass of electron $=9.0\times {10}^{-31} \mathrm{kg}$)

JEE Main 2022 (25 Jul Shift 2)

Options

• A: $1.6\times {10}^5 \mathrm{Hz}$
• B: $5.6\times {10}^5 \mathrm{Hz}$
• C: $2.8\times {10}^6 \mathrm{Hz}$
• D: $1.8\times {10}^6 \mathrm{Hz}$

Question

Given below are two statements:

Statement I: For diamagnetic substance $-1\le \mathrm{x}<0$, where $\mathrm{x}$ is the magnetic susceptibility.

Statement II: Diamagnetic substance when placed in an external magnetic field, tend to move from stronger to weaker part of the field. In the light of the above statements, choose the correct answer from the options give below.

JEE Main 2023 (10 Apr Shift 2)

Options

• A: Both Statement I and Statement II are False
• B: Statement I is correct but Statement II is false
• C: Statement I is incorrect but Statement II is true
• D: Both Statement I and Statement II are true

Question

The current required to be passed through a solenoid of $15 \mathrm{cm}$ length and $60$ turns in order to demagnetise a bar magnet of magnetic intensity $2.4\times {10}^3 \mathrm{A} {\mathrm{m}}^{–1}$ is ________ $\mathrm{A}$.

JEE Main 2023 (10 Apr Shift 1)

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Question

Match List-I with List-II :

Choose the correct answer from the options given below :

JEE Main 2024 (06 Apr Shift 2)

Options

• A: (A)-(IV), (B)-(I), (C)-(III), (D)-(II)
• B: (A)-(I), (B)-(III), (C)-(II), (D)-(IV)
• C: (A)-(III), (B)-(IV), (C)- (I), (D)-(II)
• D: (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Question

The coercivity of a magnet is $5 \times 10^3 \mathrm{~A} / \mathrm{m}$. The amount of current required to be passed in a solenoid of length $30 \mathrm{~cm}$ and the number of turns 150 , so that the magnet gets demagnetised when inside the solenoid is _____A.

JEE Main 2024 (08 Apr Shift 2)

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