# A flat coil, the area of which is 0.001m ^ 2, is located perpendicular to the lines of induction of a uniform

**A flat coil, the area of which is 0.001m ^ 2, is located perpendicular to the lines of induction of a uniform magnetic field. Find the absolute value of the EMF arising in the coil if the field induction decreases uniformly from 0.5 to 0.1 T in 4 * 10 ^ -4s.**

S = 0.001 m ^ 2.

B1 = 0.5 T.

B2 = 0.1 T.

t = 4 * 10 ^ -4 s.

∠α = 0 °.

EMF -?

According to Faraday’s law of electromagnetic induction, the EMF of induction is determined by the formula: EMF = – ΔF / t, where ΔF is the change in the magnetic flux, t is the time of the change in the magnetic flux.

The “-” sign in the formula shows the direction of the induction current, which is determined by Lenz’s rule.

The magnetic flux Ф is determined by the formula: Ф = B * S * cosα, where B is the magnetic induction of the magnetic field, S is the area of the circuit, ∠α is the angle between B and the perpendicular to the area of the circuit.

cos0 ° = 1.

ΔФ = Ф2 – Ф1 = B2 * S – B1 * S = (B2 – B1) * S.

EMF = – (B2 – B1) * S / t.

EMF = – (0.1 T – 0.5 T) * 0.001 m ^ 2/4 * 10 ^ -4 s = 1 V.

Answer: EMF = 1 V appears in the circuit.