Which of the above two graphs $(a)$ and $(b)$ representing the human voice is likely to be the male voice? Give reason for your answer.

(A) Graph $(a)$ is likely to be the male voice.
Reason: The pitch of a sound is determined by its frequency. $A$ lower frequency corresponds to a lower pitch. In the given graph,wave $(a)$ has a lower frequency (fewer oscillations per unit time) compared to wave $(b)$. Since the male voice typically has a lower pitch than the female voice,graph $(a)$ represents the male voice.