$(i)$ Define the time period of a wave.
$(ii)$ Give the relation among speed of sound $V$,wavelength $\lambda$ and its frequency $\nu$.

(N/A) $(i)$ The time taken by two consecutive compressions or rarefactions to cross a fixed point is called the time period of a wave.
$(ii)$ The relationship between speed of sound $(V)$,wavelength $(\lambda)$,and frequency $(\nu)$ is given by the formula: $V = \lambda \times \nu$.