In a winding with an area of 50 cm ^ 2 for 0.05 s, an EMF of induction of 100 V

In a winding with an area of 50 cm ^ 2 for 0.05 s, an EMF of induction of 100 V is excited when the magnetic induction changes from 0.1 to 1.1 T. How many turns of wire are there in this winding?

S = 50 cm2 = 0.005 m2.

EMF = 100 V.

B1 = 0.1 T.

B2 = 1.1 T.

t = 0.05 s.

n -?

According to Faraday’s law of electromagnetic induction, EMF = – ΔФ / t appears in the circuit, where ΔФ is the change in the magnetic flux, t is the time of the change in the magnetic flux.

The “-” sign shows the direction of the current in the circuit.

ΔF = Δ (B * S) = S * ΔB = S * (B2 – B1).

In one turn, EMF1 = S * (B2 – B1) / t occurs.

Since there are n such turns, then EMF = n * EMF1 = n * S * (B2 – B1) / t.

n = EMF * t / S * (B2 – B1).

n = 100 V * 0.05 s / 0.005 m2 * (1.1 T – 0.1 T) = 1000.

Answer: the winding has n = 1000 turns.