Question

In an AC circuit, the average value of alternating current over one complete cycle is:

• A. Maximum
• B. Minimum
• C. Infinite
• D. Zero

Hint:

Average value of AC over a complete cycle is zero, but RMS value is non-zero.

Answer 1

The Correct Option is D

Concept: Alternating current changes direction periodically. Positive half cycle and negative half cycle are equal and opposite. Hence their net average over one full cycle becomes zero.

Step 1: Understand sinusoidal current. AC current is generally: \[ i=I_0\sin\omega t \] During first half cycle: \[ i>0 \] During second half cycle: \[ i<0 \]

Step 2: Find average over complete cycle. Average current: \[ I_{avg} = \frac1T\int_0^T I_0\sin\omega t\,dt \] Since positive and negative areas cancel each other: \[ I_{avg}=0 \]

Step 3: Final conclusion. \[ \boxed{ 0 } \]