Question

A wire loop of radius 0.40 m lies so that an external magnetic field of magnitude 0.30 T is perpendicular to the loop. The field reverses its direction, and its magnitude changes to 0.20 T in 2.5 s. Find the magnitude of the average induced emf in the loop during this time.

Answer 1

The magnitude of the average induced emf in the loop is 0.1 volts.

Step-by-step explanation:

let Ф be the flux in the loop, B be the magnetic field and A be the area of the loop.

the induced emf in the loop is given by:

ε = - dФ/dt

= - d(B×A)/dt

= - A×d(B)/dt

= - π×r^2×d(B)/dt

= - π×(0.40)^2×(0.20 - (-0.30))/(2.5 - 0)

= 0.1 volt

Therefore, the magnitude of the average induced emf in the loop is 0.1 volts.