Question

The figure shows four wire loops, with edge lengths of either $Lor2L$. All four loops will move through a region of uniform magnetic field $\overrightarrow{B}$ (directed out of the page) at the same constant velocity. Rank the four loops according to the maximum magnitude of the e.m.f.$\left(e\right)$ induced as they enter the field.

• A. $(e_c=e_d)<(e_a=e_b)$
• B. $(e_c=e_d)>(e_a=e_b)$
• C. $e_c>e_d>e_b>e_a$
• D. $e_c<e_d<e_b<e_a$

Answer 1

The correct option is B $(e_c=e_d)>(e_a=e_b)$


Emf induced ina loop depends upon the length of the wire which cuts the magnetic field.($e=Blv$)
Here,
(Length of $c$ = Length of $d$) > (Length of $a$= Length of $b$).
So
$(e_c=e_d)>(e_a=e_b)$
Hence, correct answer is option (b).