The magnetic flux linked with a closed circular loop of radius 20 cm and resistance 2 ohm at any instant is phi=4t+3 where phi is in milli weber and time t in sec. find (1)flux linked with loop at t=3 sec.(2)induced emf at t=2 sec.
on differentiating the equation we get dphi/dt =4 .therefore using the formula of induced emf we get e=-dphi/dt. therefore induced emg is equal to -4mv and for flux putting t=3 in equation we get 15 mW.