Solar radiation is incident on a planet, whose surfac4ysj; 2m:s ctq6(axzfe absorbs 65% of incident intensity. What is the albedo of txzm2 :c tyfsj6s ;4aq(he planet?

  The orders of energy transformations in threea1+ n bt-elo-k 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 and ndh1 khi*i(vyy ) s2zf8on-renewable source of ez ifys2v)dh ( i1k*8yhnergy?

  Which of the following pairswc bve) o6/8bw2v;cs k constitutes a renewable and non-renewable source of ev 8e/) s2oc;6wcbvbkw nergy?

  Which of the followiny do;knvdd ,+4g is a non-renewable energy resource?

  Which of the following energy resources is non-renewablecf7k13ji v k.xyu-:b1j lh p )cqvkt23?

  The government of a medium sized city plans to repla6ev zd57 )dltzrx m/-yce coal power plants with photovolr6vm- l 7dxy)/5zdteztaic 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 ti-ze .6yt r0omy(t4:y n +gtorwmes the orbi: ytzw4gy+(-ttr.e6mn oo0yr tal radius of earth. Estimate the solar constant of Neptune.

  The following three statements give possible reasons wj c -,+xcqcod ,b1a-imhy the average intensity of sunlight incident oc+ci1-xqjoba d,- m, cn a solar panel 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 powes4fm pkynbu , u3z7v(o2/s b;:fx5fqqr stations. Examples of electricity generation that bqnps; u ox b/uvb fm2k3q57 4fzs(:f,yoth involve energy transfer from thermal to electrical are

  The albedo at the poles of Earth durin s36ydij-ji+9sf3fw lg a particular day is 0.8. What is the value of the absorbed intensity if the so-fijs l+jsf3di 93y w6lar intensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surf l az+lgael2 +qdf/g;gxm* /1yace of the earth. Some of this energy is scattered and th+adgym eggz1q +f;2la/ *l/ lxe 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 intewau2y6okh-o i:kr5 k.nsity 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 specific energy of 8 u .sy+9,ugl* fu2gcpvrv c;w:0$MJkg^{−1}$.
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 albezbqm2k3 p/jhq66q pp2do 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.