JEE PYQ: Magnetism And Matter Question 8
Question 8 - 2020 (05 Sep 2020 Shift 2)
An iron rod of volume $10^{-3}$ m$^3$ and relative permeability $1000$ is placed as core in a solenoid with $10$ turns/cm. If a current of $0.5$ A is passed through the solenoid, then the magnetic moment of the rod will be:
(1) $50 \times 10^2$ Am$^2$
(2) $5 \times 10^2$ Am$^2$
(3) $500 \times 10^2$ Am$^2$
(4) $0.5 \times 10^2$ Am$^2$
Show Answer
Answer: (2) $5 \times 10^2$ Am$^2$
Solution
$M = (\mu_r - 1) \times \frac{N}{l} \cdot iV = 999 \times \frac{10}{10^{-2}} \times 0.5 \times 10^{-3} \approx 500 = 5 \times 10^2$ Am$^2$
BETA
