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 semi-circular loop of radius $30 \mathrm{~cm}$ wire carries current $6 \mathrm{~A}$. An uniform magnetic field $0.5 \mathrm{~T}$ is present perpendicular to the plane of the loop. What is the magnitude of force exerted on the wire?
PhysicsMagnetic Effects of CurrentJEE Main
Options:
  • A $0.9 \mathrm{~N}$
  • B $1.8 \mathrm{~N}$
  • C $0.8 \mathrm{~N}$
  • D $1.4 \mathrm{~N}$
Solution:
1589 Upvotes Verified Answer
The correct answer is: $1.8 \mathrm{~N}$
Given, the radius of a circular loop,
$$
R=30 \times 10^{-2} \mathrm{~m}
$$
current, $I=6 \mathrm{~A}$ and magnetic field, $B=0.5 \mathrm{~T}$.
Force exerted on the wire,
$$
\begin{array}{rlrl}
& F & =I L B \sin \theta \\
\Rightarrow \quad & F & =6 \times 2 \times 30 \times 10^{-2} \times 0.5 \times \sin 90^{\circ} \\
\Rightarrow \quad & & {\left[\because \theta=90^{\circ} \text { and } \sin 90^{\circ}=1\right]} \\
& =1.8 \mathrm{~N}
\end{array}
$$
Hence, the correct option is (2).

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.