Mechanical Aptitude Test Mechanical Aptitude Heat Transfer and Thermodynamics Questions and Answers 2

Question 1

The First Law of Thermodynamics is best described as:

Accepted Answer

Energy cannot be created or destroyed, only converted

Answer

Heat always flows from cold to hot

Answer

Entropy of a closed system always increases

Answer

Work equals force times distance

Question 2

In a heat engine, after performing useful work, waste heat is exhausted into:

Accepted Answer

The cold reservoir

Answer

The hot reservoir

Answer

The working fluid

Answer

The crankshaft

Question 3

A pressure cooker cooks food faster because increased pressure inside the vessel:

Accepted Answer

Raises the boiling point of water above 100°C

Answer

Lowers the boiling point of water

Answer

Directly increases heat from the burner

Answer

Circulates steam more rapidly

Question 4

Thermal expansion in metals means that when temperature increases, the metal will:

Accepted Answer

Expand as atomic vibrations increase spacing

Answer

Contract and become denser

Answer

Become harder and more brittle

Answer

Only change length, not volume

Question 5

The Carnot efficiency of a heat engine depends on:

Accepted Answer

Only the absolute temperatures of the hot and cold reservoirs

Answer

The specific working fluid used

Answer

The physical size of the engine

Answer

The operating pressure of the fluid

Question 6

An adiabatic process is one in which:

Accepted Answer

No heat is exchanged between the system and its surroundings

Answer

Temperature remains constant throughout

Answer

Pressure remains constant throughout

Answer

Volume remains constant throughout