Heat & Thermodynamics MCQs with Answers

Matter changes state from solid to liquid and from liquid to gases, when it?

• A.Gains energy
• B.Loses energy
• C.Remains at constant temperature
• D.None of these

The average distance covered by a gas molecule between successive collisions is known as _?

• A.Molecular range
• B.Collision diameter
• C.Mean free path
• D.Diffusion length

With the increase of temperature, viscosity ?

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

What is the value of heat energy (Q) in an adiabatic process?

• A.Depends on the gas
• B.1
• C.Infinite
• D.0

A thermodynamic process taking place at constant volume is known as _ process.

• A.Isobaric
• B.Isothermal
• C.Isochoric
• D.Adiabatic

Thermal energy transfer required to change a liquid into gas without changing its temperature is called?

• A.Latent heat of fusion
• B.Latent heat of vaporization
• C.Specific heat capacity
• D.Thermal conductivity

A Carnot engine whose sink is at 300K has an efficiency of 40%. By how much should the temperature of the source be increased so as to increase its efficiency by 50% of the original efficiency?

• A.150K
• B.375K
• C.300K
• D.250K

Absolute temperature is the temperature at which _?

• A.Water freezes
• B.Mercury expands
• C.Water boils
• D.All molecular motion ceases

During the night time, the air above the land loses heat and its density ?

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

Boiling point is low for liquid with ?

• A.High surface tension
• B.Very low vapour pressure
• C.High density
• D.Very high vapour pressure