A square frame of wire `abcd` of side `1 m` has a total resistance of `4 Omega`.It is pulled out of a magnetic field `B=1 T` by applying a force of `1 N` (figure).It is found that the frame moves with constant speed.Find (a)this constant speed. (b)the `emf` induced in the loop, (c) the potential difference between the points `a` and `b` and (d)the potential difference between the points `c` and `d`.

Answer

A, B, C, D

Explanation

(a)`F=ILB=epsilon/R(LB)=(B^(2)L^(2)V)/R1=V//4, V=4 m//s`
`3.2xx10^(-5)=((0.02)^(2)(8xx10^(-2))^(2)xxV)/2`
(b)`epsilon=BVL=1xx4xx1=4 `Volt
( c)`V_(ab)=epsilon-IR_(ab)=4-(4//4)(1)=3V`
`V_(cd)=IR_(cd)=(4//4)(1)=1` Volt