Question

Please show neat work on how o get to the answers

A 200-loop coil of cross sectional area 8.5 cm2 lies in the plane of the page. An external magnetic field of 0.060 T is directed out of the plane of the page. The external field decreases to 0.020 T in 12 milliseconds.

(a) What is the magnitude of the change in the external magnetic flux enclosed by the coil?                  (4.0 × 10^-3 T ∙ m²)

(b) What is the magnitude of the average voltage induced in the coil as the external flux is changing? (0.57 V)

(c) If the coil has a resistance of 4.0 ohms, what is the magnitude of the average current in the coil? (0.14 A)

Answer 1

here,

number of loops , N = 200 loop

area of coil ,A = 8.5 cm^2 = 8.5 * 10^-4 m^2

the rate of change of magnetic feild , dB/dt = ( 0.06 - 0.02) /(0.012)

dB /dt = 3.33 T/s

a)

the magnitude of the change in the external magnetic flux enclosed by the coil , phi = N * area * B

phi= 200 * 8.5 * 10^-4 * (0.06 - 0.02 ) T.m^2

phi = 4 * 10^-3 T.m^2

b)

the magnitude of the average voltage induced in the coil as the external flux is changing , V = N * area * dB /dt

V = 200 * 8.5 * 10^-4 * 3.33 V

V = 0.57 V

c)

the magnitude of the average current in the coil , I = V /R

I = 0.14 A