Physics Circle home Student Login

Home›Chapters›Magnetic Properties of Materials PYQs›Field of a Magnet & Magnet in a Uniform Field›Question 5

JEE Main 2025 (3 Apr, Shift 2) · Field of a Magnet & Magnet in a Uniform Field

Field of a Magnet & Magnet in a Uniform Field question from JEE Main 2025 (3 Apr, Shift 2)

Q5JEE Main 2025 · 3 APR · SHIFT 2Medium

Field of a Magnet & Magnet in a Uniform Field

A magnetic dipole experiences a torque of 803 N m80\sqrt{3}\text{ N m} when placed in uniform magnetic field in such a way that dipole moment makes angle of 60∘60^\circ with magnetic field. The potential energy of the dipole is:

Show answer and solution

Answer: (b)

  1. τ=MBsin⁡60∘=803⇒MB32=803⇒MB=160\tau = MB\sin 60^\circ = 80\sqrt{3} \Rightarrow MB\frac{\sqrt{3}}{2} = 80\sqrt{3} \Rightarrow MB = 160
  2. U=−MBcos⁡60∘=−160×12U = -MB\cos 60^\circ = -160 \times \frac{1}{2}
  3. So the answer is (b) −80 J-80\ \text{J}.
Report a mistake

More questions on Field of a Magnet & Magnet in a Uniform Field