9702/52/F/M/20: A student investigates the discharge of a capacitor through a resistor as shown in Fig. 2.1. The student initially closes the switch and charges the capacitor. The switch is then opened and a stop-watch is started. The capacitor discharges through the resistor. At different times t the current I is measured. It is suggested that I and t are related by the equation
\( I = \dfrac{E}{R} e^{-\frac{t}{RC}}\)
where E is the e.m.f. of the power supply, C is the capacitance of the capacitor and R is the resistance of the resistor.
