JEE Mains 2018 (Code C) - Answers & Solutions - Q No ... · 24. B Medium Carboxylic Acids and Derivatives 25. A Medium Hydrocarbons 26. D Medium Chemical Equilibrium 27. C Medium

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QNo. Answer Level Chapter

1. A Medium IonicEquilibrium

2. A Medium IntroductiontoOrganicChemistry

3. C Easy Pblock-I

4. D Medium Alcohols,EthersandPhenols

5. B Hard RedoxReactions

6. A Medium IonicEquilibrium

7. C Medium Thermodynamics

8. C Medium P-BlockElements-II

9. B Medium Electrochemistry

10. B Easy ChemicalBonding

11. B Easy Pblock-I

12. C Easy ChemicalBonding

13. B Hard Amines

14. B Easy SolidState

15. B Medium ChemicalBonding

16. C Hard CoordinationCompounds

17. B Medium Hydrogen

18. D Easy Biomolecules,PolymersandChemistryinEverydaylife

19. C Hard Amines

20. B Medium EnvironmentalChemistry

21. A Medium CoordinationCompounds

22. B Easy Hydrocarbons

23. C Hard BasicConceptsofChemistry

24. B Medium CarboxylicAcidsandDerivatives

25. A Medium Hydrocarbons

26. D Medium ChemicalEquilibrium

27. C Medium Alcohols,EthersandPhenols

28. B Hard IonicEquilibrium

29. D Medium ChemicalKinetics

30. C Medium Solutions

31. A Medium IndefiniteIntegration

32. D Medium ConicSections-II

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JEE Mains 2018 Code C - Answers & Solutions



33. A Medium ConicSections-II

34. D Medium VectorAlgebra

35. B Medium ComplexNumbers

36. D Hard DefiniteIntegration

37. C Hard BinomialTheorem

38. B Medium SequenceandSeries

39. B Easy Statistics

40. D Easy Trigonometry

41. A Hard Sets,RelationsandFunctions

42. D Medium PermutationsandCombinations

43. C Hard ApplicationsofDerivatives

44. B Hard Limits

45. C Medium DefiniteIntegration

46. A Medium Probability

47. C Medium 3DimensionalGeometry

48. A Hard Trigonometry

49. B Medium StraightLines

50. A Hard SequenceandSeries

51. C Medium ConicSections-II

52. B Medium ConicSections-I

53. D Hard ContinuityandDifferentiability

54. B Medium MatricesandDeterminants

55. D Medium MathematicalReasoning

56. A Medium MatricesandDeterminants

57. B Medium Inequalities

58. C Medium ConicSections-II

59. B Medium DifferentialEquations

60. A Medium 3DimensionalGeometry

61. D Hard WaveOptics

62. D Hard ModernPhysics

63. B Easy SemiconductorElectronics

64. B Easy UnitsandMeasurement

65. A Medium MagneticEffectsofElectricCurrent

66. A Medium Electrostatics

67. A Easy DynamicsofMotion

68. B Medium Work,Power,EnergyandMomentum

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69. D Medium Capacitors

70. A Medium Oscillations

71. D Medium ModernPhysics

72. B Medium MagneticEffectsofElectricCurrent

73. A Easy CurrentElectricity

74. B Easy ElectromagneticWavesandCommunicationSystems

75. B Easy WaveOptics

76. B Medium CurrentElectricity

77. D Hard Rotation

78. A Hard Work,Power,EnergyandMomentum

79. B Medium ElectromagneticWavesandCommunicationSystems

80. D Easy ACCircuits

81. A Medium Motionin1D

82. A Easy CurrentElectricity

83. B Hard Gravitation

84. C Medium ModernPhysics

85. A Easy ACCircuits

86. B Medium ThermodynamicsandKineticTheoryofGases

87. B Medium MechanicalPropertiesofSolids

88. D Hard Waves

89. D Medium Work,Power,EnergyandMomentum

90. C Hard Rotation

SolutionsQ1. (A)

isasaltofweakacid andstrongbaseThenetsolutionwillbebasic.

Q2. (A)Kjeldahl'smethodisnotapplicabletocompoundscontainingnitrogeninnitro ,azogroups andnitrogenpresentinringsasnitrogenofthesecompoundsdoesnotconverttoammoniumsulphateundertheconditionsofthismethod.

Q3. (C)Both and arelewisacids.

Q4. (D)

Q5. (B)Weakbase(WB) StrongAcid(SA) AcidicsolutionWhenweakbaseistitratedagainststrongacidinthepresenceofmethylorangeasindicatorthentheendpointisobtainedinacidicconditionsThecolourchangeofmethylorangeisfromyellowtopinkishred.



Q6. (A)

Q7. (C)

GivenAtconstantvolume, (from stlaw)

Atconstantpressure,From stlaw

Q8. (C)

Q9. (B)

Electrolysisof involves transferofFor , transferisrequired.

ofelectricity

Q10. (B)Structureof is

Totalnumberoflonepairs



Q11. (B)

dissolve

oxide

(usedinchromatographyasadsorbent)Q12. (C)

ElectronicConfiguration BondOrder

Q13. (B)

Theabovecompoundformsresonancestabilizedcationwith andthereforeismostacidic.(IV)issecondaryamineand(I)isprimaryamine.Secondaryaminesaremorebasicthanprimaryamines.

In(II),thenitrogenis hybridizedunlikeotheralkylaminewhichare hybridized.Hence,itistheleastbasiccompound.

Q14. (B)Infrenkeldefect,thecationisdislocatedfromitsnormalsitetoaninterstitialsite.

Q15. (B)isanioniccompound. and havecovalentbonds.

Q16. (C)Oxidationstate

Oxidationstate



Q17. (B)Oxidisingactioninacidicmedium

Reducingactioninbasicmedium

Q18. (D)

Q19. (C)ThisisawrongquestioninJEE .Thequestionasksabouthistamine.However,thegivenisofhistidine.Also, ofhumanbloodisbasicandthisinformationismissing.Solution:

ofhumanbloodisofthetwonitrogensinaromaticringofaliphaticnitrogen

Thetwonitrogensinaromaticringareequivalentastheyshowtautomerism.At (humanblood),aliphaticnitrogencangetprotonatedbutnotaromaticnitrogen.

Q20. (B)

Q21. (A)

Q22. (B)



Q23. (C)

isthecompleteamountofoxygen requiredtoburnSince containshalfasmuchasoxygenrequired.

isthecompleteamountofoxygenrequired.

foroptionC,

Hence,OptionCiscorrect.Q24. (B)

Q25. (A)

Q26. (D)Forexothermicreaction,

Onlylines and showsthat increaseswith



Q27. (C)

Q28. (B)

Given,mmolesof mmolesmmolesof mmoles.

Finalvolumeofsolutionconcentrationof

Theconc.of inthefinal solutionismmolesof mmolesfinalvolume

&Volof addedInitialvolumeconcentrationof initially

Q29. (D)Letrateofdecompositionofacetaldehydebewhen reacted

(1)when reacted,

(2)Takingratioofequations weget

TheorderofthereactionisQ30. (C)

For1modalaqueoussolution,thecompoundwithlowestvalueof willhavehighestfreezingpoint.

OptionCwillhavethehighestfreezingpoint.



Q31. (A)

Divideby

Q32. (D)

Tangentsat & intersectatChordofcontact

Area



Q33. (A)

(equationoftangent)

(equationofnormal)

anglebetween &

Q34. (D)

...(i)

...(ii)Solving(i)&(ii),weget



Q35. (B)

Q36. (D)

Shadedregion,

Q37. (C)

Sumofcoefficientofodddegrees

Sumofcoefficients



Q38. (B)

Given,

....(1)Also,

....(2)Fromeqn.(1)&(2),weget:

andNow,



Q39. (B)

Given,

....(1)

Also,

....(2)

Now,

[Fromeqn.(1)&(2)]

Standarddeviation,Q40. (D)

.Q41. (A)

Wehave,

then,orAndthen,

Now, Also,

Allthepointsinset willlieinsidetherectangle.Therefore, .



Q42. (D)differentNovels

differentdictionaries

Novels Dictionary

.Q43. (C)

when

so willbelocalmaximumvaluewhen

so willbelocalminimumvalue.Q44. (B)

.

Q45. (C)

(1)

(2)

Add(1)&(2)

.



Q46. (A)CaseIEvent1:Takingoutaredball.Event2:Takingoutaredballafteraddingtworedballs.

CaseIIEvent1:Takingoutablackball.Event2:Takingoutaredballafteraddingtwoblackballs.

Totalprobability .Q47. (C)

Let andPlane:

Eqn.of

liesonplane

Similarly,Eqn.of

liesontheplane



Q48. (A)

RestallsolutionsarenotinSumSo

Q49. (B)Lettheslopeofline be

Eqn.ofline

CoordinatesofCoordinatesof

....(1)&

....(2)

Q50. (A)



Q51. (C)(Set-C)

LetSlopeoftangentonellipseSlopeoftangentonpaprabola

curvesareatrightangle,hence

Q52. (B)Orthocentre centroid and

Centroiddividesorthocentreandcircumcentreinratio

Now

Radiusofcirclewith asdiametreis.

Q53. (D)

wecheckdifferentiabilityat &At

,sofunctionisdifferentiableatAt

,sofunctionisdifferentiableatset isemptyset, .



Q54. (B)

Put

Put

orderedpair is .Q55. (D)

isequivalentto .Q56. (A)

(1)(2)(3)

Eq(2) Eq(1)(4)

fromeq(3)&(4),weget

also



Q57. (B)

: (1)

or or

But Hence, isaccepted&

isrejected:

or

[ isrejectedbecause

So containsonly elementsOption(B).

Q58. (C)

centre Eqoftangenttoparabolaat is

Q59. (B)

Put

at

at



Q60. (A)Planepassesthroughlineofintersectionoffirsttwoplanesis

(1)

ishavinginfinitenumberofsolutionwith and then

Solving

perpendiculardistancefrom is .Q61. (D)

Indiffraction

Young'sfringewidth[ -separationbetweentwoslits]

Q62. (D)FromRydberg’sformula

(1)

From (2)

From(1)&(2)

Q63. (B)

Silicondiodeisinforwardbias.Hence,acrossdiodepotentialbarrier



Q64. (B)

Q65. (A)Radiusofcircularpathinmagneticfieldisgivenby

whereK=kineticenergyofparticlem=massofparticleq=chargeonparticleB=magneticfieldintensityr=radiusofpathForelectron

...(i)Forproton,

...(ii)Foralphaparticle

Since ,theorderofradiuswillbe .Q66. (A)

Potentialat(Potentialdueto ) (Potentialdueto ) (Potentialdueto )

Potentialdueto :

Potentialdueto :

Potentialdueto :

Addingall,weget

Q67. (A)FBDforrest,

[Since, isstaticinnature]



Q68. (B)

Now,sinceparticleisundercentralactionforce.

[Note signindicatescentralacting]

Now,TotalEnergy

Q69. (D)

Q70. (A)Forsilveratom,no.ofatomsin mole Weknowthat

[where isreducedmass]

Q71. (D)Aneutronandadeuteriumareofcomparablemasses,andunderelasticcollisionconditions,analyticallywecansay,thatthedeuteriumwillgainafinalspeedcomparabletoneutron'sinitialspeed.Thisinenergytermsfortheneutroncanbestatedasahighamountoflossasitalmosttransfersallofitsenergytodeuterium.

However,withcarbonnucleus( timesthemassofneutron),theneutronwillbouncebackwillalmostthesamespeed,resultinginverysmalllossorsmalltransferenceofitskineticenergy.

Option onlysatisfiestheabovelogic.Q72. (B)



Q73. (A)

Now

.Q74. (B)

Available

.Q75. (B)

& passaxisareparallel.(1)

Let betheintensitypassingthrough' '(2)

.



Q76. (B)

&Onsolvingthethreeequationsweget

& .

Q77. (D)UsingSuperpositionPrinciple

[Massofsmallerpositionwillbe ,sinceareaofsmallerdiscistimesofentiredisc.]

Q78. (A)

Finally

And

Putting&

Relativevelocity .Q79. (B)

Letairbereferredtoasmedium1andthemediumasmedium2.

where

(refractiveindexofmedium )

.Q80. (D)

Qualityfactor



Q81. (A)

A)isincorrectbecausefrom to ,positionanddistanceshouldbesame.

thisshouldbeoptionA).Q82. (A)

volt.Q83. (B)

.

Q84. (C)

forLymanseries,serieslimit

forPfundseries,serieslimit.

Q85. (A)Averagepower

Watts.Wattlesscurrent



Q86. (B)

.Q87. (B)

.

Q88. (D)

Velocity

frequency .Q89. (D)

.Q90. (C)

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JEE Mains 2018 (Code C) - Answers & Solutions - Q No ... · 24. B Medium Carboxylic Acids and Derivatives 25. A Medium Hydrocarbons 26. D Medium Chemical Equilibrium 27. C Medium