Question 21: AC fundamentals

Question

In which of the following circuit do we find the current and voltage in phase?

Accepted Answer

In a purely resistive circuit (Option A), the voltage across and the current through the resistor are in phase.
Ã¢ÂÂ¢ OhmÃ¢ÂÂs law:
$$V = I\,R$$
Since R is a real quantity, the phase angle ÃÂ between V and I is zero (ÃÂ = 0ÃÂ°).
By contrast:
Purely inductive: current lags voltage by 90ÃÂ° (ÃÂ = Ã¢ÂÂ90ÃÂ°).
Purely capacitive: current leads voltage by 90ÃÂ° (ÃÂ = +90ÃÂ°).
Series LC: V and I are only in phase at the resonance frequency, not generally.

Answer

A purely resistive circuit

Answer

A circuit in which an inductor and a capacitor are in series.

Answer

A purely Inductive circuit

Answer

A purely capacitive circuit

AC fundamentals

In which of the following circuit do we find the current and voltage in phase?

Choose the correct answer: