What is the time constant of a capacitive circuit?
1) The time taken by the voltage to rise to 0.5 times the final value of the voltage
2) The time taken by the voltage to rise to 2.0 times the final value of the voltage
3) The time taken by the voltage to rise to 0.632 times the final value of the voltage
4) The time taken by the voltage to rise to 0.868 times the final value of the voltage