What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?
Answer220 seconds
Two 220-microfarad capacitors in parallel total 440 microfarads. Two 1-megohm resistors in parallel total 500 kilohms. Their RC time constant is 0.000440 × 500,000 = 220 seconds.