If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21 %. The original charge on the capacitor is

Question

If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21 %. The original charge on the capacitor is (A) 10 C (B) 20 C (C) 30 C (D) 40 C

Tardigrade Admin · Accepted Answer

According to question ((qf2/2 C)-(qi2/2 C)/(qi2)2 C) × 100=21 and qf-qi=2 Solving, we get qi=20 C.

Q. If the charge on a capacitor is increased by $2$ coulomb, the energy stored in it increases by $21%$ . The original charge on the capacitor is

10 C

20 C

30 C

40 C

According to question
$\frac{\frac{q _{f}^{2}}{2 C} - \frac{q _{i}^{2}}{2 C}}{\frac{q _{i}^{2}}{2 C}} \times 100 = 21$
and $q_{f} - q_{i} = 2$
Solving, we get $q_{i} = 20 C$ .

Q. If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21%. The original charge on the capacitor is