In the Circuit Shown, Both Resistors Have the Same Value $\tau$

Multiple Choice

In the circuit shown, both resistors have the same value R. Suppose switch S is initially closed and capacitor C is charged. When switch S is then opened, the circuit has a time constant $\tau$ _a. Conversely, suppose S is initially open and capacitor C is uncharged. When switch S is then closed, the circuit has a time constant $\tau$ _b. The ratio $\tau$ _a/ $\tau$ _b is:

A) 0.5
B) 0.67
C) 1
D) 1.5
E) 2