IB Thermal Physics MCQ questions ( Higher)
Thermal energy is transferred through the glass windows of a house mainly by A.
conduction and convection.
radiation and convection.
The first law of thermodynamics may be expressed in terms of the quantities below. DU, the increase in the internal energy of the system
Q, the energy transferred to the system by heating
W, the work done on the system
Which one of the following is a correct statement of the law? A.
W = DU + Q
W = −DU − Q
W = DU − Q
W = −DU + Q
A well-insulated container is divided into two equal volumes by a wall. In one half there is an ideal gas and the other is a vacuum as shown below.
The wall is now removed. Which one of the following correctly gives the changes, if any, that take place in the internal energy and entropy of the gas? Internal energy|Entropy|
A.|stays the same|stays the same|
B.|stays the same|increases|
C.|decreases|stays the same|
Two bodies are brought into thermal contact with each other. No thermal energy transfer takes place between the bodies. It may be deduced therefore, that the bodies must have the same A.
specific heat capacity.
An ideal gas expands isothermally, doing 2500 J of external work in the process. The thermal energy absorbed by the gas in this process is A.
less than 2500 J.
equal to 2500 J.
more than 2500 J.
Which one of the following correctly describes the changes, if any, of the kinetic energy and the potential energy of the molecules of a liquid as it is boiling? Kinetic energy|Potential energy|
D.|stays constant|stays constant|
The diagram shows the pressure / volume (p/V) diagram for one cycle PQRS of an engine.
In which sections of the cycle is work done on the engine?
SP and PQ only
RS and SP only
A gas is contained in a cylinder fitted with a piston as shown below.
When the gas is compressed rapidly by the piston its temperature rises because the molecules of the gas A.
are squeezed closer together.
collide with each other more frequently.
collide with the walls of the container more frequently.
gain energy from the moving piston.
A metal ball at a temperature of 200°C is suspended in an evacuated container. The walls of the container are kept at a constant temperature of 100°C.
Which one of the following statements about the temperature of the ball is correct? A.
It will eventually reach absolute zero.
It will remain constant at 200°C.
It will eventually become 100°C.
It will eventually reach a constant temperature between 200°C and 100°C. 10.
The diagram below shows energy transfers in a heat pump operating between two reservoirs at temperatures TH and TC (TH > TC). Which of the following gives the correct relationship between W, QC and QH? A.
W > QH − QC
W < QH − QC
W = QH − QC
W = QH + QC
The specific latent heat of vaporization of a substance is defined as the amount of thermal energy required to A.
change a liquid to vapour at constant pressure.
change a liquid to vapour at constant temperature.
change unit mass of liquid to vapour at constant pressure. D.
change unit mass of liquid to vapour at constant temperature. 12.
Which one of the following is a correct statement of the second law of thermodynamics? A.
When the state of a system changes its entropy increases. B.
When the state of a system changes its entropy decreases. C.
The total entropy of the universe is increasing with time. D.
The total entropy of the universe is decreasing with time. 13.
An operating refrigerator with its door open is placed in a thermally insulated room.
The refrigerator operates for a long period of time. Which of the following correctly gives the...
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