A square loop of area 25 cm$^2$ has a resistance of 10 $\Omega$. The loop is placed in uniform magnetic field of magnitude 40.0 T. The plane of loop is perpendicular to the magnetic field. The work done in pulling the loop out of the magnetic field slowly and uniformly in 1.0 sec, will be
Solution
<p>From energy conservation</p>
<p>Work done to pull the loop out = Energy is lost in the resistance</p>
<p>Emf in the loop $$ = {{d\phi } \over {dt}} = {{B \times A} \over t} = {{40 \times 25 \times {{10}^{ - 4}}} \over {1s}} = 0.1\,V$$</p>
<p>Energy lost $= {{em{f^2}} \over R} = {{{{(0.1)}^2}} \over {10}} = {10^{ - 3}}\,J$</p>
About this question
Subject: Physics · Chapter: Electromagnetic Induction · Topic: Motional EMF
This question is part of PrepWiser's free JEE Main question bank. 66 more solved questions on Electromagnetic Induction are available — start with the harder ones if your accuracy is >70%.