1. What is the phenomenon that best explains why greenhouse gases absorb infrared radiation? D. Diffraction (Total 1 mark)

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1 1. What is the phenomenon that best explains why greenhouse gases absorb infrared radiation? A. Resonance B. Interference C. Refraction D. Diffraction 2. In which of the following places will the albedo be greatest? A. A forest B. A grassland C. An ocean D. A polar ice cap 3. A wind turbine produces a power P when the wind speed is v. Assuming that the efficiency of the turbine is constant, the best estimate for the power produced when the wind speed becomes 2v is A. 2P. B. 4P. C. 6P. D. 8P. IB Questionbank Physics 1

2 4. A spherical black body has absolute temperature T 1. The surroundings are kept at a lower absolute temperature T 2. What is the net power per unit area lost by the body? A. σt 1 4 B. σt 2 4 C. σ(t 1 4 T 2 4 ) D. σ(t T 2 4 ) 5. The design of a nuclear power station includes an electrical generator. The function of the generator is to convert A. nuclear energy to kinetic energy. B. kinetic energy to thermal energy. C. thermal energy to electrical energy. D. kinetic energy to electrical energy. 6. What is the unit of surface heat capacity? A. J kg 1 K 1 B. J K 1 C. J m 2 K 1 D. J m 3 K 1 IB Questionbank Physics 2

3 7. Which of the following fuels has the highest energy density? A. Coal B. Gas C. Oil D. Uranium 8. The Sankey diagram of a fossil-fuelled power station is shown below. Which of the following best identifies the thermal energy removed by water and the useful electrical energy output of the station? Thermal energy removed Useful electrical energy output A. 2 1 B. 2 3 C. 3 1 D. 1 2 IB Questionbank Physics 3

4 9. World energy resources include coal, nuclear fuel and geothermal energy. Which of the following lists these resources in order of primary energy use in the world? A. nuclear, geothermal, coal B. nuclear, coal, geothermal C. coal, geothermal, nuclear D. coal, nuclear, geothermal 10. Which of the following processes leads to the production of a nucleus of plutonium-239 from a nucleus of uranium-238? A. Neutron capture by uranium nucleus B. Radioactive decay of uranium nucleus C. Electron capture by uranium nucleus D. Nuclear fission of uranium nucleus IB Questionbank Physics 4

5 11. Water is contained in a tidal basin behind a dam. The water has a depth h at high tide and zero at low tide, as shown in the diagram. The gravitational potential energy of the water stored in the basin between a high tide and a low tide is proportional to A. h. B. h. C. h 2. D. h Which of the following describes the role of the atmosphere in the greenhouse effect? A. The atmosphere is transparent to all solar radiation. B. The atmosphere absorbs infrared radiation from the ground. C. The atmosphere scatters red light more than blue light. D. Clouds in the atmosphere prevent absorption of infrared radiation. IB Questionbank Physics 5

6 13. Degraded energy is energy that is A. stored in the Earth s atmosphere. B. available from non-renewable energy sources. C. converted into work in a cyclical process. D. no longer available for the performance of useful work. 14. Which of the following correctly describes both the role of the moderator and of the control rods in a nuclear reactor? Moderator Control rods A. slows down the neutrons maintain a constant rate of fission B. cools down the reactor extract thermal energy C. cools down the reactor maintain a constant rate of fission D. slows down the neutrons extract thermal energy 15. Which of the following correctly shows the energy change in a photovoltaic cell and in a solar heating panel? Photovoltaic cell Solar heating panel A. solar electrical solar thermal B. electrical thermal solar electrical C. solar electrical electrical thermal D. electrical thermal solar thermal IB Questionbank Physics 6

7 16. A coal-fired power station has a power output of P and its efficiency is ε. It burns a mass of coal M every second. The best estimate of the energy density of the coal used is A. PεM B. C. D. M P P M P M 17. Critical mass refers to the amount of fissile material that A. will allow fission to be sustained. B. is equivalent to 235 g of uranium. C. will produce a growing chain reaction. D. is the minimum mass necessary for fission to take place. 18. The annual variations of solar power incident per unit area at a particular point on the Earth s surface is mainly due to the change in the A. distance between the Earth and the Sun. B. angle at which the solar rays hit the surface of the Earth. C. average albedo of the Earth. D. average cloud cover of the Earth. IB Questionbank Physics 7

8 19. Each square metre of the Sun s surface emits S joules per second. The radius of the Sun is r, and the Sun is at a mean distance R from the Earth. Which of the following gives the solar power incident per unit area of the top layer of the Earth s atmosphere? r A. S R 2 r B. S R R C. S r R 2 D. S r IB Questionbank Physics 8

9 20. The diagram shows a simple climate model for Earth. The temperature of the ground is T g and is assumed to radiate as a black body. The temperature of the atmosphere is T a and has an emissivity ε. In the model, the intensity radiated from the ground equals the intensity radiated from the atmosphere towards the ground. What is the ratio T g? T a A. ε 4 B. ε 1 C. 4 D The unit of energy density of a fuel is A. J m 2. B. J m 3. C. J kg 1. D. kg J 1. IB Questionbank Physics 9

10 22. The average temperature of the surface of the Sun is about 20 times more than the average surface temperature of the Earth. The average power per unit area radiated by the Earth is P. The average power per unit area radiated by the Sun is A. 20 P. B. 400 P. C P. D P. 23. A thermal power station is 20 % efficient and generates useful electrical power at 1000 MW. The fossil fuel used has an energy density of 50 MJ kg 1. The mass of fuel in kg consumed every second is given by which of the following? A B C. 4 D. 100 IB Questionbank Physics 10

11 24. Venus and Earth may be regarded as behaving as black bodies. The mean temperature at the surface of Venus is about 600 K and at the surface of Earth is about 300 K. Which of the following is the best estimate for the ratio power radiatedper unit area on Earth? power radiatedper unit area on Venus A. B. C. D The commercial production of energy by nuclear fusion is not yet possible mainly due to difficulties with A. obtaining plentiful supplies of a suitable fuel. B. reaching the high temperatures required. C. confining the hot plasma. D. disposing of the radioactive waste products. IB Questionbank Physics 11

12 26. A wind generator produces 5.0 kw of power for a wind speed of 6.0 m s 1. The best estimate for the power produced for a wind speed of 12.0 m s 1 is A. 10 kw. B. 25 kw. C. 40 kw. D. 125 kw. 27. Two black bodies X and Y are at different temperatures. The temperature of body Y is higher than that of body X. Which of the following shows the black body spectra for the two bodies? IB Questionbank Physics 12

13 28. The diagram below shows a simplified model of the energy balance for Earth. The albedo of the Earth according to this model is equal to 2 A B C D IB Questionbank Physics 13