Question Detail

PHY 102 Current Electricity Objective Question

Question

When a charged capacitor in an RC circuit is disconnected from the battery and allowed to discharge, how does the current behave over time?
Options
A It increases exponentially.
B It decreases exponentially.
Correct Answer
C It remains constant.
D It increases linearly.
Correct Answer

Option B is the correct answer.

Detailed Explanation

As shown in graph (a) on page 27 and page 29 for a discharging capacitor, the current starts at an initial value and then decreases exponentially, approaching zero as the capacitor discharges. The text notes the direction is opposite to charging, hence it often appears as a negative exponential decay.

Hint

As the capacitor loses charge, the potential difference across it (and thus the voltage driving the current) also decreases.

Question Info