Question

Find the potential drop across $4\mu \text{F}$ capacitor and $6\Omega$ resistor as shown in the following circuit.

• A. $0,0$
• B. $0\text{V},3\text{V}$
• C. $0\text{V},2\text{V}$
• D. $2\text{V},0\text{V}$

Answer 1

The correct option is D $2\text{V},0\text{V}$

A fully charged capacitor draws no current, hence no current flows through the branch having capacitor.
The current through the circuit is $I=\frac{3}{2+4}=\frac{1}{2}\text{A}$
Potential drop across $4\Omega$ resistor is $V=IR=\frac{1}{2}\times 4=2\text{V}$
The whole potential drop occurs across $4\mu \text{F}$ capacitor as current does not flow through the branch containing the capacitor. So, the potential drop across $6\Omega$ resistor is zero.