A circuit has an area of 0.4m² and consists of 50 loops of wire. If the loops are twisted and allowed to rotate at a constant angular velocity of 10 rads−¹ in a uniform magnetic field of 0.4T, the amplitude of the induced voltage is

A. 8V
B. 16V
C. 20V
D. 80V

Correct Answer:

Option D – 80V

Explanation

The induced voltage = time rate of change of magnetic flux

i/e E =	NΔ∅_B
	Δt

But ∅_B = Magnetic Flux
= Magnetic Induction (B) x (A)
= 0.4T x 0.4m²
= 0.16 volt second

i/e E =	NΔ∅_B
	Δt

= 0.16 x 10 x 50
= 80 volts