In the circuits in Figures P19.67, P19.70, and P19.72, assume the resistance values are...

In the circuits in Figures P19.67, P19.70, and P19.72, assume the resistance values are and and with capacitances and The emf is The switches are labeled S.

The capacitors in Figure P19.72 are initially uncharged when the switch is closed. Make a sketch of how the current through the circuit varies with time after the switch is closed. What is the time constant for this circuit?