An electrical engineer wishes to operate a heating element directly from the
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
An electrical engineer wishes to operate a 40Ω heating element directly from the 230V, 50Hz mains by connecting it in series with an inductor and a standard capacitor of 4.0μF. The aim is to make the combination resonate at 50Hz so that the current through the heater is maximised.
(i) Determine the inductance that must be connected in series for the circuit to be in resonance at 50Hz.
(ii) Calculate the rms current flowing through the circuit at resonance.
(iii) Find the power factor and hence the real power consumed by the circuit at resonance.