A uniform magnetic field B is directed into the page.A circular circuit of radius r containing a
resistor R and a capacitor C, is placed in this field. Initiallythe capacitor is uncharged, and at time t =
0, the magnitude of the magnetic field starts to change at a ratedB/dt = x, x > 0.
a) Using Lenz’s law, determine the direction of the induced currentin the closed loop. Justify
your answer.
b) Calculate the induced emf Æ and draw its direction.
c) Write an equation for the circuit as a function of time.
d) Q(t) for this circuit is given as Q(t) = C Æ (1−e −t/RC); whatis the voltage VC across the
capacitor as a function of time?
e) What is the power dissipated by the resistor at t = 0 ?
