Magnetic Properties of Matter JEE Main previous year questions with solutions

5 solved JEE Main questions on Magnetic Properties of Matter, free to read — no sign-in needed. The full chapter has 58 questions; sign in to attempt the remaining 53 in the exam simulator.

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1. Q1JEE Main 2026 (23 Jan, Shift 1)Magnetic Materials and their Properties
   Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Consider a ferromagnetic material : Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains. Reason (R): At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature. In the light of the above statements, choose the correct answer from the options given below :
   1. A.(A) is true but (R) is false
   2. B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
   3. C.(A) is false but (R) is true
   4. D.Both (A) and (R) are true and (R) is the correct explanation of (A)
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   Answer: (B)

   Assertion (A) states that individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact to form domains. This is a correct description of the domain theory of ferromagnetism, where exchange interactions lead to spontaneous alignment of moments within small regions called domains. Reason (R) states that at high temperatures (above the Curie temperature $T_C$), the domain structure disintegrates due to thermal agitation, and the material becomes paramagnetic. This is also a correct statement regarding the temperature dependence of ferromagnetic materials. However, Reason (R) describes the effect of temperature on the domain structure, whereas Assertion (A) describes the fundamental nature and formation of domains in the ferromagnetic state. The disintegration of domains at high temperature is not the reason why they form spontaneously at lower temperatures. Therefore, both statements are true, but (R) is not the correct explanation of (A).
2. Q2JEE Main 2025 (07 Apr, Shift 2)Magnetism and Properties of Magnet
   Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason(R). Assertion (A) : Magnetic monopoles do not exist. Reason (R) : Magnetic field lines are continuous and form closed loops. In the light of the above statements, choose the most appropriate answer from the options given below :
   1. A.Both $(\mathrm{A})$ and $(\mathrm{R})$ are correct but $(\mathrm{R})$ is not the correct explanation of (A)
   2. B.(A) is correct but $(\mathrm{R})$ is not correct
   3. C.Both $(\mathrm{A})$ and $(\mathrm{R})$ are correct and $(\mathrm{R})$ is the correct explanation of (A)
   4. D.(A) is not correct but ( $\mathrm{R}$) is correct
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   Answer: (C)

   Both statements are correct and reason is also the correct explanation of assertion.
3. Q3JEE Main 2023 (31 Jan, Shift 1)Magnetic Moment
   A bar magnet with a magnetic moment $5.0A{m}^{2}$ is placed in parallel position relative to a magnetic field of $0.4T$. The amount of required work done in turning the magnet form parallel to antiparallel position relative to the field direction is ________.
   1. A.$4J$
   2. B.$1J$
   3. C.$2J$
   4. D.Zero
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   Answer: (A)

   For a bar magnet, the work done in turning from parallel to antiparallel position relative to the field direction is $W=MB\left(\cos {\theta }_{1}-\cos {\theta }_{2}\right)$, here, ${\theta }_{1}=0^{\circ}and{\theta }_{1}=180^{\circ}$. $W=-MB\cos 180^{\circ}\left(-mB\cos 0^{\circ}\right)$ $W=2MB=2\times 5\times 0.4=4J$
4. Q4JEE Main 2020 (02 Sep, Shift 1)Transformers
   Magnetic materials used for making permanent magnets $\left(P\right)$ and magnets in a transformer $\left(T\right)$ have different properties of the following, which property best matches for the type of magnet required?
   1. A.$T:$ Large retentivity, small coercivity
   2. B.$P:$ small retentivity, large coercivity
   3. C.$T:$ Large retentivity, large coercivity
   4. D.$P:$ large retentivity, large coercivity
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   Answer: (D)

   As per the properties of Magnetic substances, materials favorable for permanent magnets should have high retentivity, large coercivity and high permeability.
5. Q5JEE Main 2017 (02 Apr)Magnetic Equipments
   A magnetic needle of magnetic moment $6.7\times {10}^{-2}A{m}^{2}$ and moment of inertia $7.5\times {10}^{-6}kg{m}^{2}$ is performing simple harmonic oscillations in a magnetic field of $0.01T$. Time taken for $10$ complete oscillations is:
   1. A.$8.76s$
   2. B.$6.65s$
   3. C.$8.89s$
   4. D.$6.98s$
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   Answer: (B)

   Time period of oscillating magnetic needle is $T=2\pi \sqrt{\dfrac{I}{MB}}$ $=2\pi \sqrt{\dfrac{7.5\times {10}^{-6}}{6.7\times {10}^{-2}\times 0.01}}\sec$ $=0.6647\sec$ Time for oscillations, $t=10T=6.647\sec ⁡=6.65\sec$