Resistances in the circuit of fig. are of R $$\Omega$$ each. The switch is initially open. What happens to the lamp's intensity when the switch is closed?

The equivalent inductance seen at terminals $$A-B$$ in Fig. is .................... $$H.$$

In the circuit of Fig, the switch $$'S'$$ is closed at $$t=0$$ with $${i_L}\left( 0 \right) = 0$$ and $${V_C}\left( 0 \right) = 0.$$ In the steady state, $${V_C}$$ equals

The time constant of the network shown in Fig. is