Question

A capacitor is connected in an electric circiut. When key is pressed, the current in the circuit is:

• A. zero
• B. maximum
• C. any transient value
• D. depends on capacitor used

Answer 1

The correct option is B maximum

When a fully charged capacitor with capacitance $C$ is connected in an electric circuit which contains a resistor $R$, then discharging of capacitor takes place. Initially the current in the circuit is maximum but it decreases with time and ultimately becomes Zero.

At any instant current in the circuit during discharging, $I_C=\frac{V_o}{R}{e}^{-\frac{t}{\tau }}$ where $\tau =RC$