# A rectangular loop PQMN with movable arm PQ of length 10cm and resistance 2ohm is placed in a magnetic field of 0.1 Tesla in a plan perpendicular to the loop . The resistances of arm MN, NP,MQ ate negligible. Calculate the emf induced in arm PQ and the current induced in the loop when the arm PQ is moved with velocity 20 m/s.

Here in this problem let us solve the part (ii) at first .

Now the magnetic field = B = $0\xb71$ T , velocity of PQ arm = v = 20 /s , length of the PQ arm is l = 10 cm = $0\xb71$ m

Therefore the emf induced in the arm PQ is ,

$e=Blv=0\xb71\times 0\xb71\times 20=0\xb72V$

Again ,for the part (i) of the question the resistance of the arm PQ is , R=2 ohm .

Therefore the current induced in the PQ arm is , $i=\frac{e}{R}=\frac{0\xb72}{2}=0\xb71A$

Regards

**
**