Question

Assertion - Variation in air pressure do not affect the speed of sound when temperature remains constant.
Reason - Speed of sound is directly proportional to square root of pressure.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Speed of sound, $\nu =\sqrt{\frac{\lambda P}{\rho }}$.
For a given gas, if $\rho$ remains same, the velocity would increase with increase in pressure. But at constant temperature, change in pressure is accompanied by change if volime. So, $\frac{P}{\rho }$ remains constant.
The correct reason is that $P$ and $\rho$ vary in the same manner and the velocity of sound depends upon the ratio $\frac{P}{\rho }$.