Question

Mean value of alternating current in a full cycle is:

• A. \( \frac{7}{\pi} \)
• B. \( \frac{4}{\pi} \)
• C. 2
• D. zero

Hint:

Mean value over half cycle is non-zero, but over full cycle, positive and negative halves cancel out.

Answer 1

The Correct Option is D

An alternating current (AC) varies sinusoidally with time, completing both positive and negative half cycles in each full cycle. During the positive half cycle, the current flows in one direction, and during the negative half cycle, it flows in the opposite direction. When calculating the average (mean) value of the current over one full cycle, the positive and negative contributions cancel each other out because they are equal in magnitude but opposite in direction. Mathematically, this results in: \[ \text{Average value over full cycle} = 0. \] Thus, the mean value of an AC over a complete cycle is zero.