JEE PYQ: Magnetism And Matter Question 17
Question 17 - 2019 (10 Jan 2019 Shift 1)
A magnet of total magnetic moment $10^{-2},\hat{i}$ A$\cdot$m$^2$ is placed in a time varying magnetic field, $B,\hat{i}(\cos\omega t)$ where $B = 1$ Tesla and $\omega = 0.125$ rad/s. The work done for reversing the direction of the magnetic moment at $t = 1$ second, is:
(1) 0.02 J
(2) 0.007 J
(3) 0.028 J
(4) 0.014 J
Show Answer
Answer: (1) 0.02 J
Solution
$W = 2mB = 2 \times 10^{-2} \times 1 \cos(0.125) = 0.02$ J
BETA
