In the figure the magnetic flux through the loop increases a

In the figure, the magnetic flux through the loop increases according to the relation phi_B = 5.6t^2 + 9.7t, where phi_B is in milliwebers and t is in seconds. What is the magnitude of the emf induced in the loop when t = 1.8 s? Is the direction of the current through R to the right or left?

Solution

a) induced emf = rate of change of magnetic flux

= d(@b)/dt = d(5.6t^2 + 9.7t)/dt

= 11.2t + 9.7 mV

at t = 1.8 sec

e = 11.3(1.8) + 9.7 = 30.04 mV

(B) Emf will induced to oppose the changing flux.

direction of flux is out of page. and it is increasing in out of page direction.

hence flux due to induced current will in downward direction.

hence current will be clockwise.

so current through R will be right to left.

Ans : Left