Chapter 26.4, Problem 26.4TYU

The energy stored in a capacitor is equal to q²/2C. When a capacitor is discharged, what fraction of the initial energy remains after an elapsed time of one time constant? (i) 1/e; (ii) 1/e²; (iii) 1 − 1/e; (iv) (1 − 1/e)²; (v) answer depends on how much energy was stored initially.