Heat & Thermodynamics MCQs with Answers

If the temperature of the source of heat increases, the efficiency of a Carnot engine?

• A.Remains the same
• B.Decreases
• C.Increases
• D.First increases then decreases

Past Paper MCQ

For a fixed mass of gas at constant temperature, if we decrease volume, the pressure will _?

• A.Increase
• B.Decrease
• C.Remain the same
• D.First increase then decrease

Past Paper MCQ

People prefer to wear white clothes during summer because white clothes:

• A.Reflect light and do not absorb heat
• B.Absorb light and trap heat inside
• C.Are cheaper and easily available in summer
• D.Generate a cooling effect by chemical reaction

If a gas is heated in a sealed cylinder, then _ increases.

• A.Pressure
• B.Volume
• C.Mass
• D.Density

Water both freezes and melts at 0°C.

• A.Only in the presence of impurities
• B.False
• C.Only at high pressure
• D.True

If a chemical reaction can be brought about in more than one pathway, the net enthalpy change is the same provided that the initial and final states are the same. This statement is based on _?

• A.Raoult's Law
• B.Graham's Law
• C.Henry's Law
• D.Hess's Law

Hess's law states?

• A.ΔH of reaction depends on the path taken
• B.ΔH is independent of temperature
• C.ΔH total = sum of steps
• D.ΔH is always negative for spontaneous reactions

Specific heat is defined as:

• A.Heat needed to change 1 kg of solid to liquid at melting point
• B.Heat needed to raise temperature of 1 g of substance by 1°C
• C.Heat needed to raise temperature of 1 kg of substance by 1°C
• D.Heat needed to raise temperature of 1 kg of water by 1°C

As temperature of the black body is raised, the black body radiations become richer in _?

• A.Longer wavelengths
• B.Shorter wavelengths
• C.Constant wavelengths
• D.Infrared wavelengths only

Which of the following are the fundamental ways of transferring energy?

• A.Heat and work
• B.Force and motion
• C.Light and sound
• D.Electricity and magnetism