1. Systems A and B both consist of an ideal gas at initial temperature $T$. In System A, the temperature of the gas is increased. In System B, gas molecules are added with the temperature of the system remaining constant.

Which of these statements about the total intermolecular potential energy of the two systems is correct?

2. Electrons are accelerated between two conducting plates that have a potential difference of $100V$. Estimate the total energy that would be delivered to 10^21 electrons by the conducting plates.

3. An area on the Earth's surface receives an average solar intensity of 250 Wm^−2. What is the minimum area of photovoltaic cells needed to generate 2 kW of electrical power if the photocells operate at 40% efficiency?

4. Two ideal gases $A$ and $B$ of molar masses mA>mB are initially at absolute temperatures TA. The gases are mixed together. Which of the following is correct about the average random speeds vA and vB of the molecules of A and B before and after thermal equilibrium is attained?

5. Two solid substances of equal mass are heated with the same power input. The graph below shows how the temperatures of the substances vary with time during heating.

Which of the following statements are correct?

• I.	Substance $A$ has a lower specific heat capacity than Substance $B$ when they are in the same physical state.
  II.	The specific heat capacity of each substance is lower in the solid state than the liquid state.
  III.	Substance $A$ has a lower specific latent heat of fusion than Substance $B$.

6. If the current in the circuit below is 0.5 A, what is the potential difference $V$?

7. An ideal gas piston of total volume 900 cm^3 contains 600 cm^3 of air and 300 cm^3 of water at a temperature of 27°C. The system is cooled and the piston contracts at constant pressure.

What is the approximate total piston volume at the point where the water first starts to freeze?

8. An electric circuit is connected as shown. An electric current of $2A$ flows through the electric cell with an internal resistance $r$.

What is the value for $r$ ?

9. Water in a beaker is heated on a hot plate at a rate $P$. The graph shows the change in temperature of the water over time.

Which graph correctly shows the new change in temperature of the water when the rate of thermal energy transfer is increased?

The original graph is shown by the dotted line.

A.			B.
C.			D.

10. Water of mass $m$ at an initial temperature of 20 oC is provided with thermal energy at a rate $P$. Its temperature rises to 30 oC in time $t$.

The rate of energy transfer is doubled and the mass of the water is halved. What is the final temperature, in time $t$, if the initial temperature is again 20 oC?

11. Which of the graphs below best describes the change in average kinetic energy of the molecules of a beaker of water as it is heated at a constant rate until it completely boils away?

A.			B.
C.			D.

12. A student constructed the series circuit below.

After closing the switch, which of the following is true about how the temperature of component A and current in the circuit will change with time?

13. A cylinder of fixed volume contains $n$ moles of an ideal gas at constant temperature. An additional $n$ moles of the same gas is forced into the cylinder via a one-way valve without changing the temperature. Which of the following best explains the final pressure in the cylinder?

14. An ideal gas is enclosed in a syringe. The gas has a volume of 20 mL, a temperature of 20oC, and pressure of $10kPa$. The syringe is heated to 40oC, and the volume of the gas is reduced to 5 mL.

What is the new pressure?

15. The albedo at the poles of Earth during a particular day is 0.8. What is the value of the absorbed intensity if the solar intensity is 700 W m^−2?

16. Which of the following energy resources is non-renewable?

17. 100 ml of water at 20oC is poured in an aluminum container and heated at a constant rate until all of the water is boiled. After time t1 water starts to boil, and at time t2 all of the water has boiled away.

Which of the following statements are correct?

• I.	If a glass container with the same mass is used instead of aluminum, t1 increases. (cglass)
  II.	If the container with water is thermally isolated, t2 decreases.
  III.	If more water is added to the container, t1 increases.

18. Gas System A contains non-interacting molecules of negligible size at pressure P, whilst Gas Systems B and C contain large, strongly interacting molecules at pressures $10P$ and P/2, respectively.

Which line of the table correctly describes how closely the three systems resemble an ideal gas?

19. A light bulb is lit by $1kJ$ of energy being transferred to the bulb by a potential difference of $200V$. This transfer happens over a time of 2 seconds.

What is the current passing through the bulb?

20. Solar radiation is incident on a planet, whose surface absorbs 65% of incident intensity. What is the albedo of the planet?

21. A spherical object of surface area $A$ and absolute temperature $T$ can be regarded as a black body. The power of the radiation emitted from the object is $P$. What would be the power of the radiation emitted by an object with an absolute temperature of $2T$ and a surface area of A/2?

22. If the radius of a segment of wire is doubled, and its length decreases by half, by what factor does the wire's resistance change?

23. A student is using the equation $pV=nRT$ to solve for $n$ with the following percentage uncertainties in the measurements.

What is the percentage uncertainty in the calculated value of n?

24. An electron accelerates through a potential difference of $7kV$. How much work is done on the electron by the field?

25. Which of the following is a non-renewable energy resource?