Question

A 123-turn circular coil of radius 2.41 cm is immersed in a uniform magnetic field that is perpendicular to the plane of the coil. During 0.151 s the magnetic field strength increases from 50.9 mT to 96.3 mT. Find the magnitude of the average EMF, in millivolts, that is induced in the coil during this time interval.

Answer 1

Answer:

67.44 V

Explanation:

Number of turns N =123

Radius = 2.41 cm =0.0241 m

The magnetic field strength increases from 50.9 T to 96.3 T so change in magnetic field dB = 96.3-50.9=45.4 T

Time interval dt = 0.151 sec

We know that the induced emf $e=-NA\frac{dB}{dt}$

Area $A=\pi r^2=3.14\times 0.0241^2=1.8237\times 10^{-3}m^2$

Putting all these values in emf equation $e=-123\times 1.8237\times 10^{-3}\times \frac{45.4}{0.151}=-67.44\ V$ here negative sign indicates that it opposes the cause due to which it is produced