1.  The Propagation of sound waves in a gas involves which of the following ?

A. Isobaric compression and reflection
B. Isothermal compression and rarefaction
C. Adiabatic compression and rarefaction
D. Isochoric compression and reflection

Answer: Option C

Explanation:

An adiabatic process is one that occurs without transfer of heat or matter between a thermodynamic system and its surroundings. In an adiabatic process, energy is transferred only as work

Rarefaction is the reduction of an item’s density, the opposite of compression.