JEE Main20244 Apr 2024Evening ShiftPhysicsMagnetic Properties of MatterActual
The magnetic moment of a bar magnet is 0.5 Am ^2 . It is suspended in a uniform magnetic field of 8 10⁻² ~T . The work done in rotating it from its most stable to most unstable position is:
Options
- A8 10⁻² ~J
- B4 10⁻² ~J
- CZero
- D16 10⁻² ~J
Correct answer
A. 8 10⁻² ~J
Step-by-step solution
At stable equilibrium U =- mB 0^ =- mB At unstable equilibrium aligned & U =- mB 180^ =+ mB & W = U & W.D. =2 mB & =2(0.5) 8 10⁻²=8 10⁻² ~J aligned