Capacitance Question 5

Question 5 - 2024 (29 Jan Shift 1)

A capacitor of capacitance $100 \mu \mathrm{F}$ is charged to a potential of $12 \mathrm{~V}$ and connected to a $6.4 \mathrm{mH}$ inductor to produce oscillations. The maximum current in the circuit would be :

(1) $3.2 \mathrm{~A}$

(2) $1.5 \mathrm{~A}$

(3) $2.0 \mathrm{~A}$

(4) $1.2 \mathrm{~A}$

Show Answer

Answer: (2)

Solution:

By energy conservation

$\frac{1}{2} \mathrm{CV}^{2}=\frac{1}{2} \mathrm{LI}_{\max }^{2}$

$\mathrm{I}_{\max }=\sqrt{\frac{\mathrm{C}}{\mathrm{L}}} \mathrm{V}$

$=\sqrt{\frac{100 \times 10^{-6}}{6.4 \times 10^{-3}}} \times 12$

$=\frac{12}{8}=\frac{3}{2}=1.5 \mathrm{~A}$