Solar radiation is incident on a planet, whose surface absorbs 65% of io p+xppb tf/)+l5;xpj 1f5bj*nheg3tncident intensity. What i/*tnpp ;b+ h3+)pflpjxfog t15 jb5xes the albedo of the planet?

  The orders of energyh.g ec*c)s.z l transformations in three 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 constitutes a renewable anqqjloop)jf*r*v s .3 )d non-renewable source of enerjjo*)lq)*f3or qvp.s gy?

  Which of the following pairs constitutes a renewab9m;cq/s 4n8b9zdo2uuj u,c zgw y+ )ople and non-renewable source ofwzb o+,8 ymjn 2q49/;usupuzg9)cocd energy?

  Which of the following is a non-renewable energ8tlhh48sx(h /n /ulkwy resource?

  Which of the following energy resources is non-ren,tob x( 3n :,la;oem 9c5ctsbfewable?

  The government of a medium sized city plans to replace coal power plants with we0 5qh2c,h/ dec oruhm 6g8c0photovol6,uco0c2/mc0 r5 q dwgh8hheetaic 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 aroundu:d/sgp/9/t o1n1a nru l vu;t the Sun is approximately 30 times the orbital radius of earth. Estimate the sola9v /dg n1:;tuu//unpt 1lor sar constant of Neptune.

  The following three statements give possible reasons why the wrxr*qf+:k5 n0 1s+bz 5xagteaverage intensity of sunlight incident on a solar panel dur+t5:10r rgqxfs 5 znewxb*k+ aing 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 inhe 3 l6pfg;c8o/ z7pbgsw1h+o power stations. Examples of electricity generation that + ;cg7fz/oolpgewh3 ps6b8 h1both involve energy transfer from thermal to electrical are

  The albedo at the poles of Earth during a particular day is 0.8. Whaqa*i rb3hq f- +3uj;bgt is the value of3u i r*-;gb3fh qjabq+ the absorbed intensity if the solar intensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of the earth. Some of this endf7t1pp:c aj3 fmn.m(ergy is scattered7m f.p pcdfa:3j( m1tn and the rest 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 intens*un7) w g3sugn)3dn dshr lj/4ity on the 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 spels2r5bz,* fom cific 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 of a b76y,ic0pyh zi6qoltmz h(*e 3ody
(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.