Answer the following conceptual questions on a series RLC circuit driven by a…
PHYSICS · Multi-part · CBSE · Physics · Alternating Current · Alternating Current
Problem
Answer the following conceptual questions on a series RLC circuit driven by a variable–frequency AC source.
(i) Explain what is meant by the phase angle ϕ between the alternating current in the circuit and the applied alternating voltage.
(ii) Describe qualitatively how ϕ varies as the supply frequency is increased from zero to a very large value, clearly mentioning the behaviour at resonance.
(iii) Justify why the power factor equals unity at resonance and becomes zero for very low and very high frequencies.
(iv) Sketch a labelled graph (no numerical scales required) of ϕ versus frequency indicating the regions where the circuit is inductive and capacitive.