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.

What is the time constant for the circuit in Figure P19.67? Sketch how the current through the circuit and the voltage across the capacitor vary with time after the switch is closed.