Pure R, L and C Circuits
In an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to:
A. pure inductor.
B. pure capacitor.
C. pure resistor.
D. combination of an inductor and capacitor.
Choose the correct answer from the options given below:
Show answer and solution
Answer: (c)
- Current zero when voltage is maximum means a phase difference of .
- Pure inductor: current lags by . Pure capacitor: current leads by .
- L and C together: net reactance with no resistance, so phase is still .
- A pure resistor gives zero phase difference, so C is excluded.
- So the answer is (c) A, B and D only.