Solar radiation is incident on8.zrtj5 /jca 7fom(fx a planet, whose surface absorbs 65% of incident intensity. What is the albe r/fc8z.oxtaf57mj( jdo of the planet?

  The orders of energy transformations in thx ia35qxep 8*eree power stations are given;

I. chemical → thermal → kinetic → electrical
II. kinetic → kinetic → electrical
III. gravitational potential → kinetic → electrical
Which row correctly matches the type of power station with the energy transformations?

  Which of the following pairs dke5df, dy5nrp1;4 jzconstitutes a renewable and non-renewable source of enerj5drk ep;ny1, z dfd45gy?

  Which of the followin cgw e3toj-kw7ur 7vcsta13; /g pairs constitutes a renewable and non-renewable source of energy?kuj 7gr cc3 et3t-71w/v;waos

  Which of the following is a non-red1(*g.sc48 v zi;dd-mu s rksgnewable energy resource?

  Which of the following energy resourcly8v/bjaehu18 iag2wo 3k*7:ouj z h-es is non-renewable?

  The government of a medium sized city plans to replace, npmaw8wui;+ coal power plants with photovoltaic cells to+wn aumip8 ,w; power the city.
The following data are available:
Total area available for photovoltaic cells = 62.6$km^2$
Maximum intensity of light incident on photovoltaic cells = $1.36\times10^3$ $Wm^{−2}$
Average efficiency of energy conversion in photovoltaic cells = 20 %
Hours of sunshine in one month = 150 hours
1.Explain why the government's choice to reduce its reliance on coal would be beneficial to the Earth's climate.
2.Outline, in terms of energy changes, how electrical energy is generated from coal.
3.Using the data given, calculate in $GJ$ the maximum expected energy generation for one month. $Electrical energy obtained$ =    $\times10^6\,GJ$

  The average radius of Neptune'l0g e 6n gu /iujb7+xee.;szl7s orbit around the Sun is approximately 30 times the orbital radius of earth. Estimati70gbn u.7l se xz6g+je;e /ule the solar constant of Neptune.

  The following three statew(he t5)k r:czments give possible reasons why the average intensity of sunlight incident on a solar pank:r)5z tcewh (el during a day on earth is only a fraction of the solar constant.
I. Scattering of sunlight in the atmosphere
II. Rotation of the earth
III. The surface of the solar panel is not perpendicular to incident of sunlight
Which of the statements are correct?

  Several energy conversions occur in power,y0,mj9g kr/jk1yqq:tro v )a stations. Examples of electricity generation thatrqt,j y y9v1qk/)jk0ar,mo:g both involve energy transfer from thermal to electrical are

  The albedo at the poles of Earth during a particular day is 0.8. What 1k7msfa9ov cq/m43e *ozx;zdis the value ofq13om c;v f* dxkomze4/7sa 9z the absorbed intensity if the solar intensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surfacl;eszg 2kh+8q*zj i; he of the earth. Some of this energy is scattered and the rzi ;jh*slz g82kq ;e+hest reaches the earth's surface.



1.Differentiate between heat transfer methods: conduction, convection and thermal radiation.
2.At any given time, the power of the radiation of the sun absorbed by the earth's surface is $P$.
$P$is given by
$P\,=\,(1−α)SπR^2$
Where $α$ is the albedo of the earth’s surface.
(1)Show that the average intensity of radiation $I_{avg}$​ that is absorbed by the earth's surface is given by $I_{avg}$​=$\frac{(1−α)S}{4}$. ​
(2)Calculate the average intensity of the radiation that is absorbed by the earth's surface. The earth's albedo is 0.3. $I_{avg}$ =    $Wm^{-2}$
Some of the infrared radiation from the earth is absorbed and reradiated by the greenhouse gasses.
3.Explain this absorption and emission of radiation in terms of molecular energy levels.

  On a certain day, the solar intensity on l qbhz*;hzwr,g h1j.-5 ycx0o1 my4 prthe Earth's surface is 300 $Wm^{−2}$. Photovoltaic cells which have an efficiency of 20% are used to convert solar energy to electrical energy. What should be the minimum area of the photovoltaic cells to produce an output of 6.0 kW assuming that the incident light is normal to the surface of the panel?

  A natural gas plant burns fuel with a specific energysq* +y;ysjr x6 of 80$MJkg^{−1}$.
The rate of energy input of the natural gas is 1.6$GW$. What is the rate at which the fuel burns?

  1.(1)Define the albedo ofwt6 )*w rs1iztbh c2f) a body
(2)It was suggested that painting rocky mountain tops with a white chalk-based paint could help reduce the impact of global warming. In terms of albedo, explain why this could work.
2.(1)Given that the radius of the earth is $6.4\times10^6\,m$, show that at any given time, the total amount of energy incident on the earth's surface is approximately $1.8\times10^{17}\,J$ per second. P =    $\times10^{17}\,W$
(2)The average albedo of the Earth is 0.30. What is the rate at which the Earth absorbs energy from the sun?
(3)Using your answer from (b)(ii) and ignoring atmospheric effects, estimate the average temperature of the earth for which equilibrium would be established. Assume the earth's average emissivity is 0.80.T =    K
(4)Greenhouse gases in the atmosphere elevate the average temperature of the earth such that it is higher than the answer found in (b)(iii). Explain the mechanism by which this occurs.