25. The volume of a given mass of water at a temperature of T1 is V1 . The volume increases to V2 at temperature T2 . The coefficient of volume expansion of water may be calculated from

A. VT

VT

2

2

1

1

− .

B. V VT T

2 1

2 1

−−

.

C. V VV T T

2 1

1 2 1

−−( )

.

D. V VV T T

2 1

2 2 1

−−( )

.

Specimen

26. The commercial production of energy by nuclear fusion is not yet possible mainly due to difficultieswith

A. obtaining plentiful supplies of a suitable fuel.

B. reaching the high temperatures required.

C. confiningthehotplasma.

D. disposing of the radioactive waste products.

27. A wind generator produces 5.0 kW of power for a wind speed of 6.0 m s–1. The best estimate for the power produced for a wind speed of 12.0 m s–1 is

A. 10 kW.

B. 25 kW.

C. 40 kW.

D. 125 kW.

28. It is hypothesized that globalwarmingmay lead to significant changes in the average sea-level.This hypothesis assumes that

A. average rainfall will increase.

B. icebergs will melt.

C. glaciers will melt.

D. the rate of evaporation of seawater will increase.

Specimen

29. Two black bodies X and Y are at different temperatures. The temperature of body Y is higher than that of body X. Which of the following shows the black body spectra for the two bodies?

A. Intensity X

Y

B. Intensity Y

X

wavelength wavelength

C. Intensity Y

X

D. Intensity X

Y

wavelength wavelength

30. ThediagrambelowshowsasimplifiedmodeloftheenergybalanceforEarth.

incident intensity 340 W m–2

reflectedintensity radiatedintensity 100 W m–2 240 W m–2

atmosphere

re-radiated intensity 2 W m–2

Earth surface

The albedo of the Earth according to this model is equal to

A. 2340

.

B. 100340

.

C. 238340

.

D. 240340

.

Specimen

25. Theefficiencyofamodernnaturalgaspowerstationisapproximately

A. 10%.

B. 50%.

C. �5%.

D. 90%.

26. The energy source that currently provides the greatest proportion of the world’s total energydemandis

A. coal.

B. oil.

C. naturalgas.

D. uranium.

27. Inanuclearpowerstation,uraniumisusedas theenergysourceandplutonium-239 isproduced.Whichofthefollowingistrue?

A. Plutonium-239isproducedbynuclearfusion.

B. Amoderatorisusedtoabsorbplutonium-239.

C. Controlrodsareusedtoslowdownplutonium-239.

D. Plutonium-239canbeusedasafuelinanothertypeofnuclearreactor.

28. Onedisadvantageofusingphotovoltaiccellstopoweradomesticwaterheateristhat

A. solarenergyisarenewablesourceofenergy.

B. thepowerradiatedbytheSunvariessignificantlydependingontheweather.

C. alargeareaofphotovoltaiccellswouldbeneeded.

D. photovoltaiccellscontainCFCs,whichcontributetothegreenhouseeffect.

2009 May/June T1

2209-6510

29. Greenhousegases

A. reflectinfraredradiationbutabsorbultravioletradiation.

B. reflectultravioletradiationbutabsorbinfraredradiation.

C. transmitinfraredradiationbutabsorbultravioletradiation.

D. transmitultravioletradiationbutabsorbinfraredradiation.

30. Therateofglobalwarmingmightbereducedby

A. replacingtheuseofcoalandoilwithnaturalgas.

B. areductionintheEarth’salbedo.

C. areductionincarbonfixation.

D. anincreaseindeforestation.

2009 May/June T1

25. Theunitofenergydensityofafuelis

A. Jm–2.

B. Jm–3.

C. Jkg–1.

D. kgJ–1.

26. Whichofthefollowingisthebestestimatefortheoverallefficiencyofatypicalcoalpowerstation?

A. 5%

B. 30%

C. 60%

D. 90%

27. Whensunlightisincidentonasolarcellanelectriccurrentisproduced.Thisisdueto

A. atemperaturegradientwithinthecell.

B. verylongwavelengthinfraredradiation.

C. veryshortultravioletradiation.

D. thephotoelectriceffect.

2009 May/June T2

28. ThepowerperunitlengthPofanoscillatingwatercolumn(OWC)isduetotheactionofasurfacewaveofamplitudeA.WhichofthefollowingcorrectlyrelatesPandA,andcorrectlyidentifiesthenatureoftheenergyofthewatercolumn?

Relation between P and A Nature of energy

A. P∝A kinetic

B. P∝A kineticandpotential

C. P∝A2 kinetic

D. P∝A2 kineticandpotential

29. TheaveragetemperatureofthesurfaceoftheSunisabout20timesmorethantheaveragesurfacetemperatureoftheEarth.TheaveragepowerperunitarearadiatedbytheEarthisP.TheaveragepowerperunitarearadiatedbytheSunis

A. 20P.

B. 400P.

C. 8000P.

D. 160000P.

30. GlobalwarmingreducestheiceandsnowcoveronEarth.WhichofthefollowingcorrectlydescribesthechangesinalbedoandrateofenergyabsorptionbyEarth?

Albedo Rate of energy absorption

A. increase increase

B. decrease increase

C. increase decrease

D. decrease decrease

2009 May/June T2

25. WhichofthefollowingenergysourcesresultsfromthesolarenergyincidentonEarth?

A. Nuclearfission

B. Windenergy

C. Nuclearfusion

D. Geothermalenergy

26. Whichofthefollowingisarenewableandnon-renewableenergysource?

Renewable Non-renewable

A. uranium coal

B. tidal uranium

C. uranium biogas

D. naturalgas biogas

2009 Oct/Nov T0

27. A thermal power station is 20% efficient and generates useful electrical power at 1000MW.Thefossilfuelused has an energy density of 50MJkg–1. The mass of fuel in kg consumedevery second is givenbywhichofthefollowing?

A. 0.01

B. 0.25

C. 4

D. 100

28. Whichofthefollowingislikelytoincreasegreenhousegasconcentrationsintheatmosphere?

A. Usingnaturalgasinsteadofcoaltogenerateelectricalenergy

B. Incinerationofwastetogenerateelectricalenergy

C. Increaseduseofwindturbinestogenerateelectricalenergy

D. Carbondioxidecaptureandstorageatthepowerstation

29. Venus and Earth may be regarded as behaving as black bodies. The mean temperature at thesurfaceofVenusisabout600KandatthesurfaceofEarthisabout300K.Whichofthefollowingis thebestestimatefor theratio

powerradiatedperunitareaonEarthpowerradiatedperuniitareaonVenus

?

A. 12.

B. 14.

C. 18.

D. 116

.

2009 Oct/Nov T0

30. Inanuclearpowerstation,amoderatorisrequiredto

A. controltherateoffission.

B. reduceheatlossestothesurroundings.

C. reducetheenergyofhighenergyneutrons.

D. increasetheenergyoflowenergyneutrons.

2009 Oct/Nov T0

25. Thenuclearreaction

12 H + H He + n1

324

01→

isanexampleof

A. nuclearfission.

B. radioactivedecay.

C. nuclearfusion.

D. artificialtransmutation.

26. Degradedenergyisenergythatis

A. storedintheEarth’satmosphere.

B. availablefromnon-renewableenergysources.

C. convertedintoworkinacyclicalprocess.

D. nolongeravailablefortheperformanceofusefulwork.

27. Whichofthefollowingcorrectlydescribesboththeroleofthemoderatorandofthecontrolrodsinanuclearreactor?

Moderator Control rods

A. slowsdowntheneutrons maintainaconstantrateoffission

B. coolsdownthereactor extractthermalenergy

C. coolsdownthereactor maintainaconstantrateoffission

D. slowsdowntheneutrons extractthermalenergy

2010 May/June T1

28. Which of the following correctly shows the energy change in a photovoltaic cell and in asolarheatingpanel?

Photovoltaic cell Solar heating panel

A. solar→ electrical solar→ thermal

B. electrical→ thermal solar→ electrical

C. solar→ electrical electrical→ thermal

D. electrical→ thermal solar→ thermal

29. Thealbedofortheoceansislowerthanthatforglaciers.Thisisbecause,comparedtoice,seawater

A. hasagreaterdensity.

B. hasagreaterspecificheatcapacity.

C. hasagreatercoefficientofvolumeexpansion.

D. absorbsagreateramountofradiativepower.

30. Whichofthefollowingismostlikelytoreducetheenhancedgreenhouseeffect?

A. Replacetheuseofgaspoweredstationswithoilpoweredstations

B. Replacecoal-firedpowerstationswithnuclearpowerstations

C. Increasetheuseofallnon-renewableenergysources

D. Decreasetheefficiencyofpowerproduction

2010 May/June T1

25. Whichofthefollowingcorrectlyshowsarenewableandanon-renewablesourceofenergy?

Renewable Non-renewable

A. oil geothermal

B. wind biofuels

C. oceanwaves nuclear

D. naturalgas coal

26. Criticalmassreferstotheamountoffissilematerialthat

A. willallowfissiontobesustained.

B. isequivalentto235gofuranium.

C. willproduceagrowingchainreaction.

D. istheminimummassnecessaryforfissiontotakeplace.

27. The annual variations of solar power incident per unit area at a particular point on theEarth’s surface is mainlydue to the change in the

A. distancebetweentheEarthandtheSun.

B. angleatwhichthesolarrayshitthesurfaceoftheEarth.

C. averagealbedooftheEarth.

D. averagecloudcoveroftheEarth.

2010 May/June T2

28. The water in a reservoir behind a dam drops from an initial height H0 above a turbine toproducehydroelectricity. At time t = T,h =0.

h = H0

h = 0

water

dam

turbine

Thegraphshowsthevariationwithtimetoftheheighthofthewaterabovetheturbine.

hH0

00 T t

Whichofthefollowingisameasureofthemaximumtheoreticalelectricpoweravailable?

A. H0andtheslopeofthegraph

B. Tandtheslopeofthegraph

C. Tandtheareaunderthegraph

D. H0andtheareaunderthegraph

2010 May/June T2

29. EachsquaremetreoftheSun’ssurfaceemitsSjoulespersecond.TheradiusoftheSunisr,andthe Sun is at amean distanceR from the Earth. Which of the following gives the solar powerincidentperunitareaof the top layerof theEarth’satmosphere?

A.rR

S

B.rR

S

2

C.Rr

S

D.Rr

S

2

30. Thediagramshowsasimpleclimatemodel forEarth. The temperatureof theground isTgand isassumedtoradiateasablackbody.ThetemperatureoftheatmosphereisTaandhasanemissivityε .

atmosphere

ground

Inthemodel,theintensityradiatedfromthegroundequalstheintensityradiatedfromtheatmosphere

towardstheground.WhatistheratioTTg

a?

A. ε 4

B. ε

C. ε 14

D. 1

2010 May/June T2