mMCQ.

Navigation Menu

Step into mMCQ.

Launch mMCQ. diagnostic

Explore mMCQ.

MDCAT prepFree DiagnosticPricing & SubscribeSign in

Resources

Terms & Conditions

mMCQ.

© 2021 - 2025 mMCQ.All rights reserved.

WhatsApp
  1. Home
  2. MDCAT
  3. Physics
  4. Wave Motion and Sound
MDCAT
Physics
2008

Physics · Wave Motion and Sound

Work through this past-paper style MCQ, then read the full explanation. Practice more physics questions on mMCQ with adaptive practice and topic analytics.

Question

In gases, the speed of sound is inversely proportional to ______ of the density when other factors are the same.

Options
  • A

    Square root

  • B

    Square

  • C

    Third power

  • D

    Third root

Explanation

Speed of sound (v) in gas is directly proportional to square root of isothermal elasticity (K) i.e. compression-rarefaction under constant temperature, and inversely proportional to square-root of density (ρ)
This is given by Newton’s formula,
V = √ (k/ρ).
therefore , from the formula it can be seen that
v=√ (1/ρ)
Hence, speed of sound is inversely proportional to square root of the density.

a) Square root: This is the correct option. The speed of sound in a gas is inversely proportional to the square root of the density when other factors (such as pressure and temperature) are kept constant. Mathematically, this relationship can be represented as:
Speed of sound ∝ 1/√density
 

b) Square: This option is not correct. The speed of sound is inversely proportional to the square root of the density, not the square of the density. 

c) Third power: This option is not correct. The speed of sound is inversely proportional to the square root of the density, not the cube of the density. 

d) Third root: This option is not correct. The speed of sound is inversely proportional to the square root of the density, not the cube root of the density. 

Keep practising Physics

Take the free 2 minutes diagnostic to map weak topics, then unlock full Biology, Chemistry, Physics, English, and Logical Reasoning practice for PKR 15,000/month.

Start free diagnosticExplore MDCAT

Tagged under Physics · Wave Motion and Sound · 2008