AP EAPCET 23-Aug-2021 Shift 2 Paper

Given, PQ arm is moving with constant speed v perpendicular to the magnetic field B.Here, both resistances are in parallel, so their equivalent resistance, R′=

R×R

R+R

=

R

2

Now, the circuit becomes as shown in Fig. (b).Length of PQ=l
Using expression of induced emf across PQ is given by
ε=Blv ...(i)
Now, from figure (b), the equivalent resistance is Req=R′+R =

R

2

+R=

3R

2

Now, induced current in the circuit (I through PQ) is
I=εReq=

Blv

(3R∕2)

=

2Blv

3R

[From Eq. (i)]