Question

The speed of sound is minimum in_________ among the following at same temperature.

• A. Air
• B. Helium
• C. Water
• D. Steel

Answer 1

The correct option is A Air

At a particular temperature, the speed of sound is maximum in solids and minimum in gases.
$\left(\text{Speed of sound in gas}\right)<\left(\text{Speed of sound in liquid}\right)<\left(\text{Speed of sound in Solid}\right)$
Air is the mixture of different gases. The speed of sound in air is 346 m/s and in helium is 965 m/s at ${25}^{\circ }C.$
Speed of sound $\propto \frac{1}{\sqrt{\text{Density of gas}}}$
Since density of air is more than that of helium, the speed of sound in helium is more than that of air at the given temperature.
Thus, the speed of sound is minimum in air among the given options at same temperature.

Hence, the correct answer is option (a).