Question

Assume the capacitor C is initially uncharged. The following graphs may represent different quantities related to the circuit as functions of time t after the switch S is closed

Which graph best represents the voltage versus time across the resistor R?

(A) A 

(B) B 

(C) C 

(D) D 

(E) E

Answer 1

The correct option is: (A) A 

Explanation:

When the switch is closed, the circuit behaves as if the capacitor were just a wire and all the potential of the battery is across the resistor. As the capacitor charges, the voltage changes over to the capacitor over time, eventually making the current (and the potential difference across the resistor) zero and the potential difference across the capacitor equal to the emf of the battery.