Solar radiation is incident on a planet, whose surface abl61m8 g powmo6sorbs 65% of incident intensity. Wh 6m ow8omgp1l6at is the albedo of the planet?

  The orders of energy transformations2pjfzg w6 6;spw;vs6 i 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 renewablhhj , swg0qylisn6ysw v,63g 8z*+h m+e and non-renewable source of h3 v,0hiw* gw8 gq6hys ynl++mszs 6j,energy?

  Which of the following pairs constitutk57;lgxt h zzwrb5myo-o/54l es a renewable and non-renewable source of en lbr4 5kyzt -755xmzo;o wghl/ergy?

  Which of the following is a non-renewable energy resourqu*jjl n+v;2 sy4f vqsz(9dc59p8q kdce?

  Which of the following energy resources is nja,c, d f/v+hbon-renewable?

  The government of a medium sized city plans to replace coal power plants wibcab9/ v4u t023tw;phk:nuqlth photovoltaic cetcb:2q4p u3 n wlk/aut 9hb;0vlls 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 y*um9h x u6: ejf4wade+t/a) porbit around the Sun is approximately 30 times the orbital radius of earth. Estimate the solar constafe46htd/wej 9uu*y): px+ma ant of Neptune.

  The following three statements give9awoggt:vwqy/xegy/.jfo(v,*v d .) possible reasons why the average intensity of sunlight incident on a solar panel during a day on earth is only a fraction of the solao (v)/d o.q,jvg:fg yw9*.agw/vxey tr 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 statioyd98cd n: ukqu p0u;7cg)hiywy 4x; 5tns. Examples of electricity generation that both involve energy transfer dnc)ywk q 7 5d 0;tuu;i4ygc:xy98puhfrom thermal to electrical are

  The albedo at the poles of Eard gtxl6hh-y5c+lj6( l th during a particular day is 0.8. What is the val- 6xjh+ ll(c ty65dlghue of the absorbed intensity if the solar intensity is 700 $Wm^{−2}$?

  The sun radiates energy to thrzfa/gu0q 0vv 2l+ (,xbwms8ue surface of the earth. Some of this energy is scattered +lu v0fmxsrwb,(v ug qz/820aand 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 intensity on tha4kvc :whwt6*, e p1qtt5 hs0he 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 bur emi7pvim7ev8me y,dm h+ca+5 qn/i9.ns 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 of a bodk8w wqaso hlno+ (i+-1y
(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.