Solar radiation is incident on a planet, whose surface absorbs 65% of im-;m5b8a7lanqc6: n,: mbvag.jedudncident intensity. What is the albedo om7-8n5ndqm6 mbeaad ;lb:.g:aj,cuvf the planet?

  The orders of energy transformations in three power stations hqs8n/v 5r mvuin 3g1)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 pairsd nmw3+ tj/kp2l,pciguc-4 5e constitutes a renewable and non-renewable source of en p35 -jwmgcedpkc4i/lun ,t+2 ergy?

  Which of the following pairs constitutes i.9 vn(rua(hvec(,q o a renewable and non-renewable source of enerri vo,.cuh((9(aqe nvgy?

  Which of the following isj9o(jxm7;ec ahjrb02 .dr ,mw a non-renewable energy resource?

  Which of the following energy resources is qt5g 7k;qvpl +l5t6r dnon-renewable?

  The government of a medium sized city plans to replace coal power ph 2 vypaawm+eyd75: 2ly l0s/ulants with phuply 7l5dey:h av2y0w2/+as motovoltaic cells to 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's orbit around the Sun is appwt62hzn ckr14svzq6,xu ux/lq v6r2 -roximately 30 times the orbital radius of earth. Estimate the solxs qzlwt6-2 rvnrh6q,u16 4 xc2/ uvzkar constant of Neptune.

  The following three statements givu,-,v05z6qy bnxy/ p rilr/pce possible reasons why the average intensity of sunlight incident on a solar panel during aryyx,b 5ilvz/nr q/,u-pc p06 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 stations. Examplz:wuhvj, fj)u/u1 wb ew9m;24ztcm 8 nes of electricity generation that both involve energy transfer from thermal to electrical a2j8)wf1 u4bemv ,z ;:zwnumwc/ut9j hre

  The albedo at the poles of Earth during a partsccfn7pwa/ * at-/ 5-z iab)gkicular day is 0.8. What is the value of the absorbed intensity if the solar intensitsa pb n/a gf*)-itwk5z/-ca 7cy is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of the earth. Some of mspby x3 7p5ukxb(ph4p1r:b -this energy is scattered and the rest reaches the earthp(bs1 byr: pm3 p-hk4p5bx ux7'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 the Eaw9yol ravu(ple/.+rf. fo6m kg+ 2i3 arth'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 a9jg 3xu mth)k6ld13cnh/cy7 burns fuel with a specific energy 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-i yu5w +mdnoy;3;j kc of 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.