21.6 Exercise 16

The duration of a photographic flash is related to an $\text{RC}$ time constant, which is $0 . \text{100 }\mu\text{s}$ for a certain camera. (a) If the resistance of the flash lamp is $0 . \text{0400} \Omega$ during discharge, what is the size of the capacitor supplying its energy? (b) What is the time constant for charging the capacitor, if the charging resistance is $\text{800} \text{ k}\Omega$?