Question

An ac series circuit contains a resistor of 15 ohms, an inductor of 11.5 mH and a variable capacitor. If the frequency of the applied voltage is 330 Hz, to what setting should the capacitor be set if resonance is achieved? A) 54.945 μF B) 64.35 μF C) 20.23 μF D) 11 μF E) 55.2 μF

Answer 1

C) 20.23 μF

Step-by-step explanation:

R = resistance of the resistor = 15 ohm

L = inductance of the inductor = 11.5 mH = 0.0115 H

f = resonance frequency achieved = frequency of applied voltage = 330 Hz

C = Capacitance of the capacitor

For resonance to be possible

`2\pi fL = (1)/(2\pi fC)`

`2(3.14) (330) (0.0115) = (1)/(2 (3.14) (330) C)`

C = 20.23 x 10⁻⁶ F

C = 20.23 μF