Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A rectangular coil of effective area $0.05 \mathrm{~m}^2$ is suspended freely in a radial magnetic field of $0.01 \mathrm{~Wb} / \mathrm{m}^2$. The torsional constant of the suspension fiber is $5 \times 10^{-9} \mathrm{Nm} /$ degree. If a current of $300 \mu \mathrm{A}$ is passed through it, then the angle through which the coil rotates is
PhysicsMagnetic Effects of CurrentMHT CETMHT CET 2022 (07 Aug Shift 1)
Options:
  • A $60^{\circ}$
  • B $30^{\circ}$
  • C $45^{\circ}$
  • D $90^{\circ}$
Solution:
2228 Upvotes Verified Answer
The correct answer is: $30^{\circ}$
$\begin{aligned} & I=\frac{K \theta}{n B A} \\ & \therefore \theta=\frac{\mathrm{nIAB}}{\mathrm{K}}=\frac{1 \times 300 \times 10^{-6} \times 5 \times 10^{-2} \times 10^{-2}}{5 \times 10^{-9}} \\ & \therefore \theta=30^{\circ}\end{aligned}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.