Match the following

• Transonic

• Mach No > 5

• Incompressible/Subsonic

• Mach No < 0.3

• Hypersonic

• Mach No = 1

• Sonic flow

• 0.8 < Mach No < 1.2

During a high-speed test flight, Kadhar and Kishore are observing an aircraft that is traveling faster than the speed of sound. The lines at which the pressure disturbance is concentrated and generate the cone are called

• Sound waves

• Disturbance waves

• Expansion waves

• Mach waves

In a perfectly insulated environment, Lokesh observes that the gas expands without heat exchange. Which conditions are true for this isentropic process?

• Frictionless adiabatic process

• change in entropy > 0

• change in entropy = 0

• Irreversible process

In a wind tunnel experiment, Kadhar is studying air flow around a model airplane. He needs to determine the correct form of the Compressible Bernoulli's equation to analyze the pressure and velocity of the air over the wings. Which equation should he use?

In a laboratory, Jagadeesh studies gases alongside Aisha. He learns that for a ________ perfect gas, Cp and Cv are constants and independent of temperature.

Match the following

• reversible process

• change in entropy < 0

• impossible process

• change in entropy = 0

• irreversible process

• change in entropy > 0

Lokesh and his friends are by a lake, enjoying nature. Lokesh says the sound of the waves is a weak compression wave with only small changes in flow properties. Is this statement true or false?

• True

• False

While conducting an experiment on sound waves, Aanya discovers that shock waves behave differently than expected. She learns that shock waves are non-isentropic. True or False?

• True

• False

During a flight test, Jagadeesh observed that the local flow speed of the aircraft was different from the speed of sound. The ratio of the local flow speed to the critical speed of sound is called _____ ____ number.

In a wind tunnel, Atchaya observes that as air passes through a converging section, the velocity of the subsonic airflow changes. She wonders how this affects the airflow.

• decrease

• increase

• unalter