Question

Assertion: The change in air pressure affects the speed of sound.

Reason: The speed of sound in gases is proportional to the square of pressure.

Options

• Assertion is True, Reason is True: Reason is a correct explanation for Assertion

• Assertion is True. Reason is True: Reason is not a correct explanation for Assertion

• Assertion is True, Reason is False

• Assertion is False, Reason is False

Answer 1

Assertion is False, Reason is False.

Explanation:

The speed of sound in gaseous medium is given by,

`"v" = sqrt ((gamma"P")/rho)`    .....(i)

At constant temperature

PV = constant     ....(ii)

If V is the volume of one mole of a gas, then

`"density of gas"  rho = "M"/"V" Rightarrow "V"= "M"/rho`

Where M is the molecular weight of the gas.

`therefore "equation (ii) becomes,"`

`"PM"/rho = "constant"`

`Rightarrow "P"/rho = "constant as M is a constant"`

From equation (i),

`"v" = "constant" xx sqrtgamma`

Thus, change in air pressure does not effect the speed of sound.