Question

In a physics laboratory experiment, a coil with 160 turns enclosing an area of 12.8 cm2 is rotated during the time interval 3.00×10−2 s from a position in which its plane is perpendicular to Earth's magnetic field to one in which its plane is parallel to the field. The magnitude of Earth's magnetic field at the lab location is 5.10×10−5 T.

A. What is the total magnitude of the magnetic flux (initial) through the coil before it is rotated?
B. What is the magnitude of the total magnetic flux (final) through the coil after it is rotated?
C. What is the magnitude of the average emf induced in the coil?

Answer 1

(A) the total magnitude of the magnetic flux (initial) through the coil before it is rotated is 6.528 x 10⁻⁸ Wb

(B) the magnitude of the total magnetic flux (final) through the coil after it is rotated is 0

(C) the magnitude of the average emf induced in the coil is 0.348 mV

Step-by-step explanation:

Given;

number of turns of coil, N = 160 turns

area of coil, A = 12.8 cm² = (12.8 x 10⁻⁴ m²)

change in time, Δt = 0.03 s

magnitude of Earth's magnetic field, B = 5.10 × 10⁻⁵ T

(A). the total magnitude of the magnetic flux (initial) through the coil before it is rotated.

Фi = BACosθ

= (5.10×10⁻⁵)(12.8 x 10⁻⁴)(cos 0)

= 6.528 x 10⁻⁸ Wb

(B) the magnitude of the total magnetic flux (final) through the coil after it is rotated (θ = 90)

Фf = BACosθ

= (5.10×10⁻⁵)(12.8 x 10⁻⁴)(cos 90)

= 0

(C) the magnitude of the average emf induced in the coil

E = -N(Фf - Фi) / Δt

E = 160 x ( 6.528 x 10⁻⁸) / 0.03

E = 0.000348 V

E = 0.348 mV