An oscillating LC circuit consists of a 75 mH inductor and a $1.2 \mu \mathrm{~F}$ capacitor. If the maximum charge to the capacitor is $2.7 \mu \mathrm{C}$. The maximum current in the circuit will be $\_\_\_\_$ mA.

JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Electromagnetic Induction

An oscillating LC circuit consists of a 75 mH inductor and a

1.2 μ F

capacitor. If the maximum charge to the capacitor is

2.7 μ C

. The maximum current in the circuit will be

____

mA.

Answer: 9

Solution

Energy conservation in an LC circuit requires that the maximum energy stored in the capacitor equals the maximum energy stored in the inductor:

\frac{1}{2} L i_{max}^{2} = \frac{1}{2} \frac{Q _{max}^{2}}{C}

Solving for maximum current:

i_{max} = Q_{max} \frac{1}{L C} = \frac{2.7 \times 1 0 ^{- 6}}{75 \times 1 0 ^{- 3} \times 1.2 \times 1 0 ^{- 6}} = 9 mA

JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Integer answer

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