Question

A 2 F capacitor is charged by a constant 6 A charging current for 4 sec, the voltage across the capacitor will be
1. 3 V
2. 12 V
3. 48 V
4. 1.33 V

Answer 1

Correct Answer - Option 2 : 12 V

Concept:-

We know that if a charge Q is charging with a rate dt then the rate of change of charge with respect to time is current i.e.

\(I=\frac{dq}{dt}\)

And we know that charge stored in a capacitor is proportional to the voltage applied to it i.e

Q = C × V  ----(1)

Also, Q = I × t ----(2)

where  Q= charge(c) , C= capacitor(F) , V=voltage

Calculations:-

Given:

C = 2 F, I = 6 A, t = 4 sec

From equation (2):

Q= 6 × 4 = 24 coulomb

Now using equation (1):

24 = 2 × V

V = 12 V

Hence voltage is 12 V