at water has .what is the ph of pure water at this

SOLUTIONOFMOCKTEST

JEEMAINCRASHCOURSE-CRASHCOURSE(FULLTEST2)

CONDUCTEDONDOUBTNUTAPP

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Q-1-JEEMAINCRASHCOURSE-CRASHCOURSE(FULLTEST2)-

CHEMISTRY

At waterhas .Whatisthe

pHofpurewateratthistemperature?

(A)6.667

(B)

(C)

(D)

CORRECTANSWER:D

AttemptMockTestonDoubtnutApp

https://doubtnut.app.link/PpEO40MdB2

https://doubtnut.app.link/h92gK3MdB2


CHEMISTRY

Thecompound(C)is:

(A)

(B)

(C)

(D)

CORRECTANSWER:C



SOLUTION:

NA



CHEMISTRY

onreactionwith inaq.Solution

givesbluecolour.Theseareseparatedbya

semipermeablemembrane asshown.Dueto

osmosisthereis-



(A)bluecolourformationinside

(B)bluecolourformationinside

(C)bluecolourformationinbothofthesides

and

(D)nobluecolourformation

CORRECTANSWER:D




CHEMISTRY

Medicinewhichisanantibioticis:

(A)ampicillin

(B)aspirin

(C)calmpose

(D)chloroquine

CORRECTANSWER:A



CHEMISTRY

Agas atatmisbubbledthroughasolution



containingamixtureof and

at C.Ifthereductionpotentialorderis

,then:

(A)ClwilloxidiseFandnotBr

(B)ClwilloxidiseBrandnotF

(C)ClwilloxidisebothBrandF

(D)ClwillreducebothBrandF

CORRECTANSWER:B



CHEMISTRY

Thefollowingstatementsrelatedtotheadsorptionof

gasesonasolidsurface.Identifytheincorrect



statementamongthem.

(A)Onadsorption,theresidualforcesonthe

surfaceareincreased

(B)Onadsorption,decreaseinsurfaceenergy

appearsasheat

(C)Entropyofadsorptionisnegative

(D)Enthalpyofadsorptionisnegative

CORRECTANSWER:A



CHEMISTRY

TheIUPACnameofthecompoundis:



(A)2-methyl-6-oxohex-3-enamide

(B)6-keto-2-methylhexanamide

(C)2-carbamoylhexanal

(D)2-carbamoylhex-3-enal

CORRECTANSWER:A



CHEMISTRY

Anelectron,aprotonandanalphaparticlehave



kineticenergiesof16E,4EandErespectively.What

isthequantitativeorderoftheirdeBroglie

wavelengths?

(A)

(B)

(C)

(D)

CORRECTANSWER:A



CHEMISTRY



Thecompound(C)is:

(A)

(B)

(C)

(D)

CORRECTANSWER:A

SOLUTION:


The -ketoacidonheatingundergoesdecarboxy-

lationeasily.



CHEMISTRY

Wehavetwomineralsofonemetal,firstissulphide

andsecondisoxide.Thenfindthecorrectstatement

regardingextractionofmetalfromthesetwo

minerals.

(A)Sulphidemineralisgoodchoicefor

extractionofmetal

(B)Oxidemineralisgoodchoiceforextractionof

metal

(C)Anyofthesetwomaybeore,dependsonthe



concentrationofthemetalintheminerals,

durabilityoftheprocessandotherrelevant

factors

(D)Alwayssulphidemineralwillbetheore

CORRECTANSWER:C



CHEMISTRY

Thehormonewhichcontrolstheprocessofburning

offats,proteins,andcarbohydratesandliberates

energyinthebodyis:

(A)Thyroxine

(B)Adrenaline



(C)Insulin

(D)Cortisone

CORRECTANSWER:C



CHEMISTRY

Inwhichofthefollowingreaction actsasa

reducingagents?



(D)

(A) and

(B) and

(C) and

(D) and

CORRECTANSWER:C

SOLUTION:

Reducingagentsmeansthatthecompounds

undergoesoxidation,i.e.,thecompoundloses

electrons.In(B)and(D), losseselectrons.

Hence,answeris(c).




CHEMISTRY

Whichofthefollowingiserythroformandoptically

inactive

(A)

(B)

(C)

(D)



CORRECTANSWER:C



CHEMISTRY

0.5moleeachoftwoidealgases

and aretakeninacontainerand

expandedreversiblyandadiabatically,duringthis

processtemperatureofgaseousmixturedecreased

from350Kto250K.Find (incal/mol)forthe

process:

(A)

(B)

(C)



(D)Noneofthese

CORRECTANSWER:C

SOLUTION:



CHEMISTRY

Inwhichofthefollowingspecies bondis



presentbut -ppi`bondisabsent?

(A)

(B)

(C)

(D)

CORRECTANSWER:D

SOLUTION:



CHEMISTRY

Thesetofcompoundswhichdoesnotexist,is



(A)

(B)

(C)

(D)

CORRECTANSWER:A

SOLUTION:

(a).

Duetoinertpaireffect, convertsinto

ion,hence doesnotexist,

(b).

duetoinertpaireffect, ionconvertsinto

hence doesnotexist.

(c). doesnotexist,becauseofabsence


ofd-orbitalcontraction



CHEMISTRY

Thestartingmaterialof is:

(A)Monochlortrifluroethylene

(B)Tetrafluoroethylene

(C)Vinylchloride

(D)Styrene

CORRECTANSWER:A






CHEMISTRY

Forareaction products,theratelaw

expressionis

then

(A)

(B)

(C) mayormaynotbeequalto

(D)

CORRECTANSWER:C

SOLUTION:

Becauseorderofreactionisanexperimental

termstherefore,itmayormaynotbeequalto




CHEMISTRY

Thegasmainlyresponsibleforglobalwarmingis:

(A)

(B)

(C)

(D)

CORRECTANSWER:A



CHEMISTRY

Whichofthefollowingisbasic?




(A)

(B)

(C)

(D)

CORRECTANSWER:A

SOLUTION:

Acidicstrength:

.

Basicstrengthisreverse,so isbasic.




CHEMISTRY

Findthetotalnumberofdiproticacidsamongthe

following:

CORRECTANSWER:5

SOLUTION:

Diproticacidsarethosewhichfurnishtwo

protonspermolecule.


(Monobasic)

Onlythosehydrogensarereplaceableformoxy-

acidsofphosphorusandsulphurwhichare

attachedtooxygen.

(Tribasic)

(Dibasic)

(Monobasic)




CHEMISTRY

FindthenumberofmoleculeshavingtwoLonepair

ofelectronsoncentralatom.

CORRECTANSWER:5

SOLUTION:



CHEMISTRY



Amongthefollowingcompounds,thenumberoffood

preservativeis_____.

Propylgallate,butylatedhydroxylanisole,saccharin,

butylatedhydroxyltoluene,xylitol,p-hydroxybenzoic

acid,sodiumbenzoate

CORRECTANSWER:5



CHEMISTRY

Whichofthefollowingcanactasambidentate

ligand?



CORRECTANSWER:3

SOLUTION:

ambidentate



CHEMISTRY

Inabovebalancereaction,valueof willbe:

CORRECTANSWER:8





MATHS

Iftheline beatangenttothehyperbola

,then isequalto

(A)

(B)

(C)

(D)noneofthese

CORRECTANSWER:C

SOLUTION:

Theequationofthehyperbolais

.

Theline touchesthishyperbola,if


[Using ]

+-16`



MATHS

Thevalueof

,is

(A)1



(B)

(C)0

(D)noneofthese

CORRECTANSWER:C

SOLUTION:

Applying ,weget




MATHS

Theequationofthecommontangenttotheparabolas

,is

(A)



(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:

Theequationofanytangentto is

Ifitisatangenttotheparabola ,then

theequation


Puttingthevalueofmin(i),weget


Thisistheequationofthecommontangent.

ALITERTheequationofanytangentto

is

wherem'

Ifittouchestheparabola ,thenwe

musthave


Substitutingthevalueofmin(i),weobtaintha

equationoftherequiredcommontangentas



MATHS

Ifarealpolynomialofdegreensatisfiestherelation



(A)anontofunction

(B)anintofunction

(C)alwaysaonefunction

(D)alwaysamanyonefunction.

CORRECTANSWER:A

SOLUTION:

Letf(x)beapolynomialofdegreen.Then,

f'(x)andf''(x)arepolynomialofdegree(n-1)and

(n-2)respectively.


Clearly,f(x)beingapolynomialofdegree3,isan

ontofunctions.



MATHS

Ifoneofthelinesof

isabisectoroftheanglebetweenthelinesxy=0,

thenmis

(A)1

(B)2



(C)

(D)

CORRECTANSWER:A

SOLUTION:

Clearly,linesgivenbyxy=0arex=0,y=0i.e.

thecoordinateaxesandtheirbisectorsare

Putting in

,weget

Hence,option(a)iscorrect.




MATHS

If ,thenxbelongsto

(A)

(B)

(C)

(D)R

CORRECTANSWER:C





MATHS

Theprobabilityofamanhittingatargetis .Ifhe

fires,ntimessuchthattheprobabilityofhishitting

thetargetatleastonceisgreaterthan ,thenthe

valueofn,is

(A)3

(B)4

(C)5

(D)noneofthese

CORRECTANSWER:B



MATHS



Theequation has

(A)norealrootsset

(B)exactlyonerealroot

(C)tworealroots

(D)infinitelymanyrealroots

CORRECTANSWER:B



MATHS

Ifthelinesegmentjoining(2,3)and(-1,2)isdivided

internallyintheratio3:4bytheline ,

then =



(A)

(B)

(C)

(D)

CORRECTANSWER:A



MATHS

Thecircle intersectstheline

attwodistinctpoints,if

(A)

(B)



(C)

(D)

CORRECTANSWER:D

SOLUTION:

Iftheline intersectsthecircle

attwodistinctpoints,thenLengthof

perpendicularfromcentre Radius





MATHS

In ,considertheplanes and

.Let beaplane,differentfrom

and whichpassesthroughtheintersectionof

and .Ifthedistanceofthepoint(0,1,0)andfrom

is1andthedistanceofapoint from is

2,thenwhichofthefollowingrelationsis(are)true?

(A)

(B)

(C)

(D)

CORRECTANSWER:D

SOLUTION:


Theplanepassingthroughtheintersectionof

planes and is

or ..i

Itisgiventhatthedistancesofthepoint

and fromiare1and2respectively.

and

and


and

and

or





MATHS

Let and bethreenon-coplanarunitvectors

suchthattheanglebetweeneverypairofthemis

.If

,where and arescalars,thenthevalueof

,is

(A)

(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:


Wehave

Takingdotproductwith weobtain

..ii

Takingdotproductonbothsidesof(i)by ,we


get

................iii

Takingdotproductonbothsidesof(i)by we

get


..........iv

Fromiiandivweget


Putting in(iii)weget Thus,we

obtain



MATHS

Thevectors liesintheplaneofvectors and ,

whichthefollowingiscorrect.

(A)



(B)

(C)

(D)

CORRECTANSWER:A



MATHS

Thedifferentialequationoffamilyofcircleswith

fixedradius5unitsandcentreontheliney=2,is

(A)

(B)



(C)

(D)

CORRECTANSWER:A

SOLUTION:

Let(a,2)bethecentreofthecircle,where'a'is

avariable.Then,theequationofthefamilyof

circlesis

Differentiatingw.r.tox,weget


Substitutingthisvalueof in(i),weget

astherequireddifferentialequation.



MATHS

Thevalueof ,is

(A)



(B)

(C)

(D)noneofthese

CORRECTANSWER:B

SOLUTION:





MATHS

IfthetangentatapointP,withparametert,onthe

curve

meetsthecurveagainatQ,thenthecoordinatesofQ

are

(A)

(B)

(C)

(D)

CORRECTANSWER:A


SOLUTION:

Let beapointonthegiven

curve.

Now,

ThetangenttothecurveatPis


Thiswillpassthrough if


So,thecoordinatesofQare



MATHS

If ,then

(A)

(B)

(C)

(D)

CORRECTANSWER:B





MATHS

Thesetofpointswherethefunction.

Where[.]denotesthegreatestintegerfunction,is

notdifferentiable,is

(A)

(B)

(C)

(D)

CORRECTANSWER:C

SOLUTION:


Wehave

Clearly,f(x)isdiscontinuousatx=0,1,2and3.

So,itisnotdifferentiableatthesepoints.

Atx=-1,wehave

So,itiscontinuousatx=-1

Also,(RHDatx=1)=-1(afinitenumber).

Therefore,f(x)isdifferentiableatx=-1




MATHS

Letthefunction

bedefinedontheinterval[0,1].Theevenextension

off(x)totheinterval[0,1].Theevenextensionoff(x)

totheinterval[-1,1]is

(A)

(B)

(C)



(D)noneofthese

CORRECTANSWER:A



MATHS

If

(A)2

(B)1

(C)3

(D)4

CORRECTANSWER:D



SOLUTION:

Wehave,




MATHS

Thedifferentialequationofallparabolaswhoseaxis

ofsymmetryisalongx-axisisoforder

CORRECTANSWER:2



SOLUTION:

Thegeneralequationofthesaidparabolasis

,wherea,barearbitraryconstants.

So,thedifferentialequationisoforder2.



MATHS

Atpresent,afirmismanufacturing2000items.Itis

estimatedthatrateofchangeofproductionPwith

respecttoadditionalnumberofworkersxisgivenby

ifthefirmemploys25more

workers,thenthenewlevelfofproductionofitems

is

CORRECTANSWER:3500





MATHS

Ifthelinejoiningthepoints(0,3)and(5,-2)isa

tangenttothecurve thenthevalueofC

is

CORRECTANSWER:4



MATHS

If




CORRECTANSWER:3

SOLUTION:

Weknowthattheminimumvalueof

whichisattainedatx=-1




MATHS

Ina ,if

,then=c

CORRECTANSWER:2

SOLUTION:



Wehave,



PHYSICS

TwopointsPandQaremaintainedatthepotentials

of10Vand-4V,respectively.Theworkdonein

moving100electronsfromPtoQis:



(A)

(B)

(C)

(D)

CORRECTANSWER:C

SOLUTION:




PHYSICS

When5Vpotentialdifferenceisappliedacrossa

wireoflength0.1m,thedriftspeedofelectronsis

.Iftheelectrondensityinthewire

is ,theresistivityofthematerialisclose

to:

(A)

(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:


HereV=potentialdifference

l=lengthofwire

n=no.ofelectronsperunitvolumeof

conductor.

e=no.ofelectrons

Placingthevalueofaboveparametersweget

resistivity.




PHYSICS

InaYoung'sdoubleslitexperiment,12fringesare



observedtobeformedinacertainsegmentofthe

screenwhenlightofwavelength600nmisused.If

thewavelengthoflightischangedto400nm,

numberoffringesobservedinthesamesegmentof

thescreenisgivenby

(A)12

(B)18

(C)24

(D)30

CORRECTANSWER:B

SOLUTION:

,




PHYSICS

Anucleuswithmassnumber initiallyatrest

emitsan particle Q

5.5MeV

alphaparticle`

(A)

(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:


Byconservationofmomentum,

rArrK_(2)=54K_(1) Also,K_(1)+K_(2)=5.5

MeV`(ii)

solveequation(i)and(ii)



PHYSICS

Aparticleofmass isprojectedfromthegroundat

someanglewithhorizontal.Itshorizontalrangeis .

Atthehighestpointofitspathitbreaksintotwo

piecesofmasses and ,respectively,suchthat



thesmallermasscomestorest.Thelargermass

finallyfallsatadistance fromthepointof

projection,where isequalto

(A)

(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:

Applyconservationofmomentumathighest

point

.i




PHYSICS

Auniformringofradius isgivenabackspinof



angularvelocity andthrownonahorizontal

roughsurfacewithvelocityofcentretobe .The

velocityofthecentreoftheringwhenitstartspure

rollingwillbe

(A)

(B)

(C)

(D)

CORRECTANSWER:B

SOLUTION:

Here

Atpurerolling


and

(inpurerolling




PHYSICS

Inthearrangementasshown, ,densityof

liquidis anddensityofblock is .Thesystemis

releasedfromrestsothatblock movesupwhenin

liquidandmovesdownwhenoutofliquidwiththe

sameacceleration.Findthemassofblock .



(A)

(B)

(C)

(D) m

CORRECTANSWER:D


SOLUTION:

Accelerationwhenblock intheliquid.

Accelerationwhenblock isoutsideofthe

liquid

Given weget




PHYSICS

Waterrisestoaheightof inacapillarytube.If

thetubeistilted fromthevertical,waterwillrise

inthetubetoalengthof

(A)

(B)



(C)

(D)waterwillnotriseatall

CORRECTANSWER:A

SOLUTION:

Sincewaterriseofheightof inacapillary

Iftubeisat inthiscaseheightmustbeequal

to




PHYSICS

Alargechargedmetalsheetisplacedinauniform

electricfield,perpendiculartotheelectricfieldlines.

Afterplacingthesheetintothefield,theelectricfield

ontheleftsideofthesheetis

andontherightitis .Thesheet

experiencesanetelectricforceof0.08N.Findthe

areaofonefaceofthesheet.Assumetheexternal

fieldtoremainconstantafterintroducingthelarge

sheet.Use



(A)

(B)

(C)

(D)none

CORRECTANSWER:A

SOLUTION:

Letexternalfieldbe andsurfacecharge

densityofsheet

be (includingbothsurfaces).So


Electricfieldduetosheet

.......(i)

........(ii)

From(i)and(ii),

and


forceonsheet

or

or

or

.




PHYSICS

A bulbdesignedtooperateon istobe

connectedacrossa source.Findtheresistance

tobeputinseriessothatbulbconsumes only.

(A)

(B)

(C)

(D)

CORRECTANSWER:C

SOLUTION:

Resistanceofbulbis



Ifbulbconsumes ,thenpotential

differenceacrossthebulbshouldbe .So

.Andpotentialdifference

across .Soltbr




PHYSICS

Twoplates,eachofareaA,areplacedparallelto

eachotheratadistanced.Oneplateisconnectedto

abatteryofemfEanditsnegativeisearthed.The

otherplateisalsoearthed.Thechargedrawnby

plateis


(A)

(B)

(C)

(D)


CORRECTANSWER:B

SOLUTION:

ThecircuitcanberedrawnasshowninFig.

Chargeoncapacitoris

Option(a),(c),and(d)areincorrect




PHYSICS

Inanelectricfieldshowninfigure,three

equipotentialfigure,threeequipotentialsurfacesare

shown.Iffunctionareshown.Iffunctionofelectric

fieldis ,andgiventhat

,thenwehave

(A)


(B)

(C)

(D)datainsufficient

CORRECTANSWER:B

SOLUTION:

As increasingalong axis,samepotential

dropwilloccurforlesservaluesofdistance.

Hence .



PHYSICS

Electricdipoleofmoment iskeptatapoint

(x,y)inanelectricfield .Find



theforceonthedipole.

(A)

(B)

(C)

(D)

CORRECTANSWER:D

SOLUTION:




PHYSICS

Apointobjectisplacedatadistanceof25cmfroma

convexlensoffocallength20cm.Ifaglassslabof

thicknesstandrefractiveindex1.5isinserted

betweenthelensandtheobject,theimageisformed

atinfinity.Thethicknesstis

(A)10cm

(B)5cm

(C)20cm

(D)15cm

CORRECTANSWER:D



SOLUTION:

Imagewillbeformedatinfinityifobjectis

placedatfocusofthelens,i.e.,at20cmformthe

lens.Hence,

shift

or or



PHYSICS

TheKEofthephotoelectronsisEwhentheincident

wavelengthis .TheKEbecomes2Ewhenthe



incidentwavelengthis .Theworkfunctionofthe

metalis

(A)

(B)

(C)

(D)

CORRECTANSWER:A

SOLUTION:

or

or


or

or



PHYSICS

Theradiusofthesecondorbitofanelectronin

hydrogenatomis .ThedeBrogliewavelength

associatedwiththiselectroninthisorbitwouldbe

(A)

(B)

(C)



(D)

CORRECTANSWER:A

SOLUTION:

or

deBrogliewavelength



PHYSICS

ThewavelengthofthefirstlineofLymanseriesin

hydrogenatomis .Thewavelengthofthefirst



lineofLymanseriesfor timesionizedsodiumatom

willbeadded

(A)

(B)

(C)

(D)

CORRECTANSWER:D

SOLUTION:

Now,



PHYSICS



Half-lifeofaradioactivesubstance and are,

respectively, and .Initially,the

samplesof and haveequalnumberofnuclei.

After ,theratiooftheremainingnumberof

and nucleiis

(A)

(B)

(C)

(D)

CORRECTANSWER:C

SOLUTION:

Weknowthat


For ,

For ,

or .




PHYSICS

Twothindiscseachofmass andradius are

attachedasshowninfigure,tofromarigidbody.The

rotationalinertiaofthisbodyaboutanaxis

perpendiculartotheplaneofdisc andpassing

throughitscentreis:


.

(A)

(B)

(C)

(D)


CORRECTANSWER:D

SOLUTION:

.



PHYSICS

Findtheratioofelectricworkdoneinbringinga

charge from to andthatfrom to

inasphereofcharge distributed

uniformlythroughoutitsvolume.



(A)

(B)

(C)

(D)Noneofthese

CORRECTANSWER:A

SOLUTION:

Workdonebyelectricfield




PHYSICS



Acapacitorwithstoredenergy isconnected

withanidenticalcapacitorwithnoelectricfieldin

between.Findthetotalenergystoredinthetwo

capacitors.

CORRECTANSWER:2

SOLUTION:

Storedenergyofcapacitor

whentheyconnected,thechargeshared

Sothattheenergyshoulddividedthetotal

energystoredineachofthetwocapacitanceis2

J.





PHYSICS

Acylindricalvesselofheight500mmhasanorifice

(smallhole)atitsbottom.Theorificeisinitially

closedandwaterisfilledinituptoheightH.Now

thetopiscompletelysealedwithacapandthe

orificeatthebottomisopened.Somewatercomes

outfromtheorificeandthewaterlevelinthevessel

becomessteadywithheightofwatercolumnbeing

200mm.Findthefallinheight(inmm)ofwaterlevel

duetoopeningoftheorifice.

[Takeatmosphericpressure ,

densityofwater=1000kg//m^3 g=10m//s^2`.

Neglectanyeffectofsurfacetension.]

CORRECTANSWER:6

SOLUTION:


Initially,thepressureofaircolumnabovewater

is

andvolume ,whereAis

theareaofcross-sectionofthevessel.

Finally,thevolumeofaircolumnabovewateris

300A.If isthepressureofairthen

Asthetemperatureremainsconstant,according

toBoyle'slaw


Thefallofheightofwaterlevelduetothe

openingof

orifice



PHYSICS

A massissuspendedfromawireofnegligible

mass.Thelengthofthewireis1manditscross

sectionalareis .Ifthemassispulleda

littleintheverticallydownwarddirectionand



released,itperformssimpleharmonicmotionof

angularfrequency .IftheYoung'smodulus

ofthematerialofthewireis ,the

valueofnis

CORRECTANSWER:4

SOLUTION:

Weknowthat (i)

Here

Comparingtheaboveequationwith we

get

(ii)


From(i)&(ii),



PHYSICS

Theactivityofafreshlypreparedradioactivesample

is disintergrationspersecond,whosemeanlife

is .Themassofanatomofthisradioisotopeis

.Themass(in )oftheradioactive

samplesis

CORRECTANSWER:1

SOLUTION:



at

massofsample



PHYSICS



Twomutuallyperpendicularinfinitewiresalongx-

axisandy-axiscarrychargedensities .The

electriclineofforceatPisalongtheline

,wherePisalsoapointlyingonthe

sameline.Find .

CORRECTANSWER:3


SOLUTION:

Netelectricfieldis

duetoverticalwire

I -direction

duetoverticalwireinx-direction

or or or



at water has .what is the ph of pure water at this

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