7/27/2019 GRE Flash Card Corrections

1/2

7/27/2019 GRE Flash Card Corrections

2/2

PhysicsGREFlashcardsClarifications/Corrections January18,2013

Continued(twopages)

3WO

Noticehow!isdefinedbelowthehorizontal.Thisaccountsfortheminus

signin thetermintheformulaforthemaxima.

8WO Allformulasrefertoreflections.

14WO Torelatethetwopathdifferencesexplicitlyto L and L, wehave

1. m!= 2!l(constructivepath)

2. (m+1/ 2)!= 2!l (destructivepath)

where!l = | L - L'|

4RO ni>ncshouldbereplacedbyn i>ntintheanswertothethirdpart.

12RO Notethatyoucancalculateshereviathemasterformula

forfocallengthf(whichisnegativeforthefocalpointFlocatedontheright).

21RO Wemeanttojustsaylensinsteadofconverginglensonthefrontofthe

card.Bothcasesarediverging.

23RO Thea,blabelswereswitchedfortheanswers.

25RO Tostartwith,istheanglesubtendedbytheobjectattheeyesnaturalnear

pointN.isthe(bigger)anglesubtendedbytheobjectwhenwemoveit

closertoalensfocalpoint(sos=fintheanswer).Changethefiguretolook

like

3L Boththeoremscanbeintermsofequivalentvoltageorcurrentsources.

3CO ThegraphisparticleenergyEversusk.Itroughlyfollowsp2/2mbutthereare

bandsofenergywithbandgapsshownbetweenthemsee4CO.

2NP deletethesecondofcompositesinthe8thlineoftheanswer.

5NP Inaddition,allleptonshavespin1/2.

14NP Theneutrinohereisanelectronneutrino(e).

15NP Replacethe3Heinthesecondreactionby

3H(tritium).

17NP Thresholdoccurswhenallparticlespresentareatrestintheoverallcenter-

of-momentumframe.

19NP

NotefirstthatBEispositiveifthenucleusisstable(soitsmassislessthanthesumofthemassesofallitsnucleons).ReplaceN;ZbyN=Zindescriptionof

asymmetryterm(notethatBEis lessifN! Zsolessstablethen).Also,inthe

pairingeffect,decreaseshouldreadincreaseandviceversa,alongwith

(=-1)shouldread(=+1)andviceversa.Thusthepairingeffectforeven-evenandodd-oddisoppositetowhatwaswrittenthere.

5MS Deletethespuriousz2factorinthelasttermshowninthegeneralseries.

7MS ReplaceNbyN-1intheStandardDeviationforasetofsamples.

Pleasecontactus(rwb@case.edu)ifyoufindanyadditionalerrorsorambiguitiesinanyoftheflashcards.Wellbe

mostgrateful!Bestluck,DocBrown,January2013

P.S.Iammostgrateful(inalphabeticalorder)tothefollowingwonderfulpeoplewhorecentlypointedoutmany

oftheabovecorrectionsorclarifications(thislistdoesnotincludefolkswhocontributedtoearlierimprovements

fortheearlierversions)

AryaAfshari

TalEinav

CathleenFry

AllisonReinsvold

FabioSanches

! sin"i

1/s + 1/s' = 1/f < 0