An inductance of 2.0 ext H , a capacitance of 18 ext F and a resistance of 10 ext k are connected to an AC source of 20 ext V with an adjustable frequency. Determine the frequency that must be chosen to maximise the current in the circuit.

Step-by-step solution

The current in an LCR circuit is maximum at the resonant frequency. The resonant frequency is given by f = 1 2 LC Substituting the given values L = 2.0 H and C = 18 F = 18 10⁻⁶ F : f = 1 2 2.0 18 10⁻⁶ f = 1 2 36 10⁻⁶ f = 1 2 6 10⁻³ f = 1000 12 f = 250 3 Hz