Using a variable-frequency a.c. voltage source, the maximum current measured in the given LCR circuit is 50 mA for V=5sin(100t). The values of L and R are shown in the figure. The capacitance of the capacitor (C) used i $s ________$ μF.

Question

G1 Physics · Accepted Answer

The current is maximum in a series LCR circuit at resonance. Therefore, ω = 1/√(LC). From V = 5sin(100t), the angular frequency is ω = 100 rad/s. Given, L = 2 H. Hence, C = 1/(ω²L) = 1/[100²×2] = 1/(2×10⁴) = 5×10⁻⁵ F = 50×10⁻⁶ F = 50 μF. Hence the answer is 50.

Using a variable-frequency a.c. voltage source, the maximum current measured in the given LCR circuit is 50 mA for V=5sin(100t). The values of L and R are shown in the figure. The capacitance of the capacitor (C) used i s ________ μF.