Heat & Thermodynamics MCQs with Answers

Past Paper MCQ

A thermos flask keeps things close to their original temperature by reducing ?

• A.Conduction
• B.Convection
• C.Radiation
• D.All of these

The efficiency of a Carnot engine will be maximum if?

• A.T1 is equal to zero
• B.T2 is equal to zero
• C.T1 is equal to T2
• D.T1 is twice of T2

Sometimes a cycle with well inflated tyres left in the sun, has its tubes burst open. Why?

• A.Because air escapes from the tube due to expansion of the valve
• B.Because the rubber of the tube melts in the heat
• C.Because the pressure of air inside the tube increases
• D.Because the tyre rubber expands and squeezes the tube

22320 cal heat is supplied to 100g of ice at zero degree centigrade. If the latent heat of fusion of ice is 80 cal/g and latent heat of vaporization of water is 540 cal/g, the final amount of water thus obtained and its temperature respectively are _?

• A.100 g, 0°C
• B.100 g, 100°C
• C.92 g, 0°C
• D.92 g, 100°C

What is the name of the process in which heat is transferred through a fluid?

• A.Conduction
• B.Convection
• C.Radiation
• D.None of these

When the volume of a gas is held constant, increasing the temperature causes the pressure to?

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

What compensatory movement occurs when warm air rises into the atmosphere during convection?

• A.Downward movement of cooler air
• B.Horizontal movement of warm air
• C.Upward movement of cooler air
• D.Spiral movement of warm air

If ΔH > 0, the reaction is?

• A.Exothermic
• B.Endothermic
• C.Isothermal
• D.Adiabatic

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

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

The Maxwellian speed distribution provides a direct explanation of _?

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