Question

In an AC circuit, the box contains a capacitor or an inductor. The voltage across the source is as shown.


The following graphs are $V_{box}$ vs time (t) and $V_{resistance}$ vs t. Which of the following graph(s) are correct.

• A. If the box contains the inductor
  
• B. If the box contains the inductor
  
• C. If the box contains the capacitor
  
• D. If the box contains the capacitor
  

Answer 1

The correct option is B If the box contains the inductor


When the box contains an inductor, phasor diagram is



Hence $V_L$ is leading $V$ of the source. Hence A is not possible. As $V_R$ is lagging $V$. B is possible.

When the box contains a capacitor, phasor diagram is


Here $V_R$ is leading $V$ of the source. Hence C is not possible.$V_C$ is lagging $V$. D is also not possible.