To obtain the Boolean function $F(X, Y) = X\overline{Y} + \overline{X}$, the inputs $PQRS$ in the figure should be

The number of junctions in the circuit is

All the elements in the circuit are ideal. The power delivered by the 10 V source in watts is

The circuit shown in the figure with the switch S open, is in steady state. After the switch S is closed, the time constant of the circuit in seconds is