Question

The circuit pictured below shows battery, two resistors, an uncharged capacitor and a switch. The resistor values are shown.
The switch is closed, and after an average current of $2.0A$ flows for $6.0s$, the voltage across the capacitor is $4.0V$.
What is the capacitance of the capacitor?

• A. $4.0F$
• B. $3.0F$
• C. $36.0F$
• D. $12.0F$
• E. $8.0F$

Answer 1

The correct option is B $3.0F$

Given - $I=2.0A,t=6.0s$ ,

charge through the capacitor in 6.0s ,

$q=It=2.0\times 6.0=12C$ ,

now given that voltage across capacitor $V=4.0V$ ,

therefore capacitance

$C=q/V=12/4.0=3.0F$