In the RC circuit shown, the switch is closed at t = 0. The graphs of resistor voltage and capacitor voltage versus time are given. The time constant of the circuit is approximately:

Question

G1 Physics · Accepted Answer

From the graph, use the charging/discharging exponential and read the time at which the curve reaches 63.2% of its final value (or falls to 36.8%). This gives τ ≈ 145 ms. Hence B.