Solar radiation is incident on a planet, whose surface absorbs 65% of incidyqj 1jf8pd;o:f de3,h ent intens : od,jfy3 p8hdq;fej1ity. What is the albedo of the planet?

  The orders of energy transformations in three power stations are g4om(.l.hy 1vmd oyoe*iven;

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 constitutes aer tvh+4u)f pl;x84jv renewable and non-renewable source ofefh u+v44rxljv8 pt;) energy?

  Which of the following pairs constitutes a renewable and non-ren 28 x,).ppvckuka;yse ewable source of enerv2skcxy; u . ,p)ka8epgy?

  Which of the following is7mgkuqp5e:3 w 8ic n)t a non-renewable energy resource?

  Which of the following energy resources is non-renewa:t40,hgah0bp eja8)i c2saq tble?

  The government of a medium sized city plans to replace coal power plate6u-q p.wy 67 nz.fwevp5.d96c hv jjnts with photovoltaz-.devpwhp v9e .6n6jf c7 56wujy.tq ic 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 approximately 30 f ygfr4m(lgj8(x5 puh/dzo 9*times the orbital radius of hdfl5(oz p yxr9mf4g*8 (/ gujearth. Estimate the solar constant of Neptune.

  The following three statemen;v0a9*yc(t8x sg twm pts give possible reasons why the average intensity of sunlight incident on a solar panel dur; 89yx0vtwgpsat* cm (ing 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 stations. Examples of el ras /st:x5pvv4pzr3 qa) 18qyectricity generation that both involve energy transfer vv 4zpxtq )a51y :rq s/srpa83from thermal to electrical are

  The albedo at the poles of E:qq ,/tpy3qplarth during a particular day is 0.8. What is the value of the absorbed intensity if the solar intensity isyt3,/: qlqpqp 700 $Wm^{−2}$?

  The sun radiates energy to the;uvije vju. -.wn)wb1 surface of the earth. Some of this energy is scattered and the rest reaches ;1u)j- ev ijw.u.nb vwthe 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 t ) /z:eyn9/7 rq+xfhsl a gzhyt8*8niahe 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 energy of uyfdv0 ck,wq zhn,*3, 2ei2 en80$MJkg^{−1}$.
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 of a bod18mf6v 4s gzfjy
(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.