Solar radiation is incident on a planet, whose surfackpr1di a2ni3;+ hpq b0e absorbs 65% of incident intendr+ai2knip3;0 b hq1p sity. What is the albedo of the planet?

  The orders of energy transformatii8 3piunbx+1b)v 9n fdons 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 renewa 7r+alu nfz;i*8fy dvo(c.0 kable and non-renewable source of ayof0nd +7l u.rk;i*8vc za( fenergy?

  Which of the following pairs constitutes a renewable and n7 qw0amh h: u5lqr)yw+on-renewable source of energy)a5qw+h qh0y m7 ulw:r?

  Which of the following is ah2o8zod i69dbu92 uxl non-renewable energy resource?

  Which of the following enwzid7q/w 8yrfhb: j- .ergy resources is non-renewable?

  The government of a medium sized 6 j oxe3o56 3moz/lldeppxf;2 city plans to replace coal power plants with photovoltaic cells x6oejzm3o2 l5op/dxpl ; f3e6to 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',nzh37ajv zmk;1sq /ws orbit around the Sun is approximately 30 times the orbital radius of earth. Estimate the solar constant of zj s v;z,1qm/ wh7n3kaNeptune.

  The following three statements give possiblyfyt1 4yh8t ;me reasons why the average intensity of sunlight incident on a solar panel during a day on earth is only a fraction of the solar cons1tfy4;t hym 8ytant.
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 elecx7y *l+bj.baxbw:au5h/ u3oj tricity generation that both involve energbba:3 .ux/ou jaw b7 +xyh*jl5y transfer from thermal to electrical are

  The albedo at the poles of Earth during a particular -jrrdemj t1r 6e8xl8 t 78wr6f 1bis(wday is 0.8. What is the value of the absorbed intensity if the solar intlrr8tt1dj68 wr- 18 e(feiwrmsx7 bj 6ensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of the earth. Some of this ener9m7niussl(c7k qza;e 5 3-dwtgy is scattered and the rests7a zdu7-k t3qnl5is ;(mew c9 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 the Earth's surfacevtnv9h s2c 0j o*lhbnr*91e3z 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 spe1gq 84ctqak yb- oa gz+oz l-(bk)*4yfcific 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 ,)-aev wo k*rsbody
(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.