Q4
A long solenoid of radius $$R$$ carries a time (t)-dependent current $$I(t)=I_0t(1-t)$$. A ring of radius $$2R$$ is placed coaxially near its middle. During the time interval $$0\le t\le 1$$, the induced current $$(I_R)$$ and the induced $$EMF(V_R)$$ in the ring change as: