Question

A 1300-turn coil of wire that is 2.10 cm in diameter is in a magnetic field that drops from 0.130 T to 0 T in 12.0 ms. The axis of the coil is parallel to the field.

Question: What is the emf of the coil? (in V)

Answer 1

Answer:

4.875 V

Explanation:

N = 1300

diameter = 2.10 cm

radius = half of diameter = 1.05 cm

B1 = 0.130 T

B2 = 0 T

t = 12 ms

According to the law of electromagnetic induction,

$e = - N\frac{d\phi }{dt}$

Where, Ф be the magnetic flux linked with the coil

$e = - NA \frac{dB }{dt}$

$e = -1300\times3.14\times{1.05\times 1.05\times 10^{-4}\times\frac{0-0.130}{12\times10^{-3}}=$

e = 4.875 V