Solar radiation is inc 6k mi;*dbj/zdident on a planet, whose surface absorbs 65% of incident intensity. What is the albed;*b/zdkim d6jo of the planet?

  The orders of energy trane9+bnmq li,5t sformations 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 and non-renewable source ogzo h8xc6n;1 5gk jh s-/fphx)f )x8g6 op1/hf cxj -k;sh5nzgh energy?

  Which of the following pairs constitutes a renewable and non-renewable * u8gav8-vraf source of enf v8ruva -ga8*ergy?

  Which of the following is a non-renewable energy resource:lvmk ead96 9zyh+:p v?

  Which of the following energy resources is nog;4 bh9cdbfoy1 )li6 nn-renewable?

  The government of a medium sized city plans to replace coal 2a xzqvdbj-s* zuxz6- t(p) )fpower plants with photzs-- (xdz)6 f2j* t pxqazbuv)ovoltaic 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 t q6is6jpwre33 imes the orbital radiui3wje3 p sqr66s of earth. Estimate the solar constant of Neptune.

  The following three statements give possible reasons whyy4ioyw ph+0ck 5z (y*o the average intensity of sunlight incide pcy 54hwy0yo(+ik o*znt on 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 power stations.szgo;d 6i 7f72ibi0pa Examples of electricity generation that both involve energy transfer from thermal to eleci76fg;ozis2 ab 7p0i dtrical are

  The albedo at the poles of Earth during 6pcjdl 3* i edj6/hgf .sf:le.b(ii1ba particular day is 0.8. What is the value of the absorbed intensity if the solar intensie hg1le c. 6 ipdisdi:*l63.fb/bf(jjty is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of the earth. Some o6xb6s(i 7 zs+(czuofyf this energy is scattered and the rest reachecs 7+6(bo(6 zxzusyfis 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 in c1thr/6uj 1r xu7vh8itensity 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 9t ;pj -ly)5,v zc+tj,rkwfo 96maqtwa 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 (v*sd fs1g;a5/ s:pp uip gi.pa 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.