The area of a rectangular loop of wire is 3.6 × 10-3 m2. the loop is placed in a magnetic field that changes from 0.20 t to 1.4 t in 1.6 s. the plane of the loop is perpendicular to the direction of the magnetic field. what is the magnitude of the induced emf in that loop?

2.7 mV

Explanation:

A = 3.6 x 10^-3 m^2

B1 = 0.20 T, B2 = 1.4 T, t = 1.6 s

According to the Faraday's law of electromagnetic induction

e = - rate of change of magnetic flux

e = - dФ / dt

where, negative sign shows the direction of induced emf.

Ф = B x A

dФ / dt = A x dB / dt

e =  A x dB / dt = 3.6 x 10^-3 x (1.4 - 0.2) / 1.6

e = 2.7 x 10^-3 V = 2.7 mV

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27