Question

A 14.5 cm diameter loop of wire is initally oriented perpendicular to a 1.8 T magnetic field.The loop is rotated so that its plane is parallel to the field direction in 0.23 s.a.what is the average induced emf in the loop

Answer 1

Diameter of the loop d = 14.5 cm

Radius of the loop r = 7.25 cm = 7.25 *10^-2 m

Magnetic field B = 1.8 T

The loop rotated so that it's plane is parallel to the field direction in t = 0.23 sec

The average induced emf in the loop is

$e =-\frac{d\phi}{dt} =- \frac{A*B}{t}$

A = area of loop = π r^2 = π * ( 7.25*10^-2)^2

A = 0.0165 m^2

$e = \frac{0.0165*1.8}{0.23}$

e = emf = 0.129 V