Question

A square coil of side 0.5 m has movable sides. It is placed such that its plane is perpendicular to uniform magnetic field of induction 0.2 T If all the sides are allowed to move with a speed of 0.1 m/s for 4 sec outwards, average induced emf is?

zero 0.01 0.028 0.072.

please answer this!

Answer 1

A square coil of side 0.5 m has movable sides. It is placed such that its plane is perpendicular to uniform magnetic field of induction 0.2 T If all the sides are allowed to move with a speed of 0.1 m/s for 4 sec outwards, average induced emf is?

zero 0.01 0.028 0.072.

Ans. When all the four sides are allowed to move then area is changing. 
Therefore 
previous area = 0.5m x 0.5m = 0.25 sq.meter 
Area when placed in magnetic field = 1.3m x 1.3m= 1.69 sq.meter 
Induced EMF = d(nBA CosØ)dt. [where Cos Ø = 1] 
E = 0.2 x (0.25-1.69)/4 
E = 0.072 Volt
SO MARK AS BRAINIEST PLEASE.

Answer 2

Answer:

Explanation:

Here side of the square increases both sides so per second 2×0.1×4=0.8+initial area=1.3