Question

The variation of the instantaneous current (I) and the instantaneous emf (E) in a circuit is as shown in figure. Which of the following statement is correct.

• A. The voltage lag behind the current by $\pi/2$
• B. The voltage leads the current by $\pi/2$
• C. The voltage and the current are in phase
• D. The voltage leads the current by $\pi$

Answer 1

Answer: (B)

At $t=0,$ phase of the voltage is zero, while phase of
the current is $\frac{-\pi}{2},$ i.e., voltage leads by $\frac{\pi}{2}$