Heat & Thermodynamics MCQs with Answers

Evaporation can occur at ?

• A.Boiling point only
• B.Freezing point only
• C.All temperatures
• D.Room temperature only

The value of gas constant R in ergs mol⁻¹K⁻¹ is _?

• A.8.314 × 10⁷
• B.8.314 × 10⁶
• C.8.314 × 10⁸
• D.8.314 × 10⁵

Wien's displacement law is ?

• A.𝜆𝑚𝑇 = constant
• B.𝜆𝑚/𝑇 = constant
• C.𝜆𝑚 = 𝑇 × constant
• D.𝑇/𝜆𝑚 = constant

Past Paper MCQ

In a railway track, two rails are joined end to end with a gap left between them because?

• A.Steel rails are cheaper when laid with a gap
• B.Gaps help rainwater drain off the track quickly
• C.It makes the track look more uniform and aligned
• D.Accidents due to expansion in summer can be avoided

Molar heat of vaporization of water is

• A.334 kJ/mol
• B.22.6 kJ/mol
• C.40.7 kJ/mol
• D.6.01 kJ/mol

The value of molar specific heat according to classical theory is _?

• A.2R
• B.3R
• C.R
• D.5R/2

As the pressure in an ideal gas is increased isothermally, the average molecular speed _?

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

The zero kelvin means ?

• A.-273°C
• B.0°C
• C.-100°C
• D.273°C

The process in which solid directly changes to gas is called?

• A.Evaporation
• B.Sublimation
• C.Condensation
• D.Deposition

For 0 to 10 degree Celsius rise in temperature, volume of water will _?

• A.Increase continuously
• B.Decrease continuously
• C.First decrease then increase
• D.Remain unchanged