Question

Find the time constant for a R-C circuit for resistance R = 24 kohm and C = 16 microfarad.

(a) 1.5 millisecond

(b) 0.6 nanosecond

(c) 384 millisecond

(d) 384 microsecond

I have been asked this question in an international level competition.

This is a very interesting question from Resistances and Capacitances topic in division Electrostatic Boundary Value Problem of Electromagnetic Theory

Answer 1

The correct answer is (c) 384 millisecond

The best explanation: The time constant for R-C circuit is τ = RC. Put R = 24 kilo ohm and C = 16 micro farad. We get τ = 24 x 10^3 x 16 x 10^-6 = 0.384 = 384 millisecond.