1. A light dependent resistor (LDR) and a $10k\Omega$ resistor are connected in series to a $12V$ D.C supply as shown

2. The diagram below shows a circuit connected to a 12 $V$ battery with negligible internal resistance.

What is the value of the current $I$ through the $2\Omega$ resistor?

3. A circuit of a cell of electromotive force (emf) $18.0V$ and negligible internal resistance connected to three resistors of resistance $6.0\Omega$

The ammeter is ideal. What is the reading of the ammeter?

4. The work done when 1 mole of a gas expands through an adiabatic process is $120J$.

What is the change in temperature of the gas?

5. 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?

6. 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

7. 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<caluminum)
  II.	If the container with water is thermally isolated, t2 decreases.
  III.	If more water is added to the container, t1 increases.

8. Several energy conversions occur in power stations. Examples of electricity generation that both involve energy transfer from thermal to electrical are

9. 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?

10. A material with a mass of m is heated. The graph shows the variation of the temperature of the material with the energy supplied.

Which one of the following gives the specific heat capacity of the material?

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

12. The average radius of Neptune's orbit around the Sun is approximately 30 times the orbital radius of earth. Estimate the solar constant of Neptune.

13. 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.

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

What is the new pressure?

15. The variation of terminal potential difference $V$ across an electric cell with current $I$ coming out of the cell is shown in the graph.

What are the values of the emf $ϵ$ and internal resistance $r$ of the electric cell used in this circuit?

16. 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?

17. Which of the following average properties of the molecules inside piston containing an ideal gas piston stay constant when the piston expands at constant temperature?

• I.  Intermolecular potential energy.
• II.  Kinetic energy.
• III.  Frequency of collisions.

18. 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?

19. An ideal gas is enclosed in a container of fixed volume. When the temperature of the gas is27oC, its pressure is $p$. Calculate the pressure in the gas when it is heated to 54oC.

20. 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?

21. 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?

22. Which of the following real gases at atmospheric pressure would be least likely to approximate to an ideal gas?

23. The following three statements give possible reasons why the average intensity of sunlight incident on a solar panel during a day on earth is only a fraction of the solar constant.

24. The pV diagram shows the cycle of an engine. The processes $B\to C$ and $D\to A$ are adiabatic and all processes are reversible.

Which of the following statements about the engine are correct?

25. A body of water loses energy at a constant rate. Assume that the specific heat capacity of ice is half the specific heat capacity of liquid water.

Which graph shows a possible variation of temperature with time?

A.			B.
C.			D.