JEE MainPhysicsAlternating Current
An AC voltage source v = V₀ ( t) is connected across a circuit. The resulting steady-state current is given by i = I₀ ( t) . Which of the following correctly describes the possible composition of the circuit?
Options
- APure capacitor only
- BEither a pure capacitor or an LC series circuit with X_C > X_L
- CEither a pure inductor or an LC series circuit with X_L > X_C
- DLCR series circuit at resonance
Correct answer
B. Either a pure capacitor or an LC series circuit with X_C > X_L
Step-by-step solution
The given voltage is v = V₀ ( t) . The given current is i = I₀ ( t) . We can rewrite the current equation in terms of sine as i = I₀ ( t + 2 ) . This shows that the current leads the voltage by a phase angle of 2 . A phase lead of 2 occurs in a purely capacitive circuit. This can be achieved either by a pure capacitor or by an LC series circuit where the capacitive reactance is greater than the inductive reactance ( X_C > X_L ). Answer: Either a pure capacitor or an LC series circuit with X_C > X_L