detailed analysis of jee main 2015

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JEE Main 2015 question paper detailed analysis OVERALL PAPER: 1.Overview (general theme setting and touching upon briefly on all points). We can have a JEE 2014 vs 2015 approach 2.Class XI and XII break-up of syllabus 3.Difficulty level analysis - by section and overall o Question-wise difficulty level break-up o Section-wise difficulty level break-up o Questions that should've been attempted first o Questions that should've been avoided in first go 4.Time management analysis - by section and overall o Question-wise time spent break-up o Section-wise time spent break-up o Questions that should've been attempted first o Questions that should've been avoided in first go 5.Special Insights and Tricks that could've been used o 2 questions that were wrong, why? o Speed tips that could've saved time o Trick questions? Seemingly difficult but easy questions Seemingly easy but difficult questions Analysis The question papers were available in four sets- A, B, C and D. Version Order of Subjects A Physics, Chemistry, Mathematics B Chemistry, Mathematics, Physics C Mathematics, Physics, Chemistry D Physics, Mathematics, Chemistry

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Page 1: Detailed Analysis of JEE Main 2015

JEE Main 2015 question paper detailed analysisOVERALL PAPER:

1.Overview (general theme setting and touching upon briefly on all points). We can have aJEE 2014 vs 2015 approach

2.Class XI and XII break-up of syllabus3.Difficulty level analysis - by section and overall

o Question-wise difficulty level break-upo Section-wise difficulty level break-upo Questions that should've been attempted firsto Questions that should've been avoided in first go

4.Time management analysis - by section and overallo Question-wise time spent break-upo Section-wise time spent break-upo Questions that should've been attempted firsto Questions that should've been avoided in first go

5.Special Insights and Tricks that could've been usedo 2 questions that were wrong, why?o Speed tips that could've saved timeo Trick questions?

Seemingly difficult but easy questions Seemingly easy but difficult questions

Analysis

The question papers were available in four sets- A, B, C and D.

Version Order of Subjects

A Physics, Chemistry, Mathematics

B Chemistry, Mathematics, Physics

C Mathematics, Physics, Chemistry

D Physics, Mathematics, Chemistry

Page 2: Detailed Analysis of JEE Main 2015

Physics: : It was the toughest amongst the three; the questions that were included in this sectionwere a little tricky. Out of the 30 questions from Physics, only five questions were theory based,the rest 25 were numerical based questions. It was a time consuming section. Some experts alsobelieve that the questions in this section were ambiguous, which increased the difficultylevel. The topic of Thermodynamics in Physics was very tough, especially the Entropy questionswere quite unexpected. About 25% of the questions are pertaining to graphs. a few areas likewave optics, properties of liquids etc. were totally absent in the paper.

Ideal Time for Physics – (Student should invest 75 min. for this section)

Chemistry Majority of the questions in the Chemistry part of the JEE Main 2015 are in the rangeof easy to moderate. The overall difficulty level of this part in this year exam is less as comparedto last year. Usually, application level questions are expected from Physical and Organicchemistry areas, but this year questions from these two areas were quite straight in nature.However, one question from Inorganic Chemistry was based on practical part and it can be rateddifficult to answer. Moreover, this year's contribution from Inorganic Chemistry was morecompared to previous years. The questions were all fact based. This section was not very timeconsuming. Most of the questions are asked directly from the NCERT texts for Chemistry.

Ideal Time for Chemistry – (Student should invest 40 min. for this section)

Mathematics: This section, however, not difficult, was found a little lengthy by the examinees. Ithad a good mix of questions. Also, two questions were not properly framed in Mathsection. One was from Probability (All options were incorrect) and other was from DifferentialEquation. (Initial condition was not given). There was one question each from Statistics, SetRelation and Mathematical Reasoning and one easy questions from height and distancetrigonometry. All these chapters are not in JEE Advanced Syllabus. Questions from InverseTrigonometry ,3-D and Vectors were easy. Few questions, which posed difficulty, weregenuinely concept wise difficult and tricky in nature.

Ideal Time for Math – (Student should invest 65 min. for this section)

Analysis of JEE (Main) 2015 Paper -1

Page 3: Detailed Analysis of JEE Main 2015

Marks Distribution from Class XII CBSE Syllabus

Subject No. of questions Total Marks

Mathematics 14 56

Chemistry 20 80

Physics 17 68

Marks Distribution from Class XI CBSE Syllabus

Subject No. of questions Total Marks

Mathematics 16 64

Chemistry 10 40

Physics 13 52

Q.No.Topic(based on SET-A) JEE mainPaper-1 Easy Moderate Difficult

1 Kinematics

embibepredicted highweightage

2 Unit & Dimensions

embibepredicted easyto score

3 Laws of Motion

embibepredicted LowWeightage

4 Conservation of Momentum

embibepredicted easyto score (MustDo)

5 Centre of Mass

embibepredictedLowWeightage

6 Rotational Mechanics embibe

Page 4: Detailed Analysis of JEE Main 2015

predicted LowWeightage

7 Gravitation

embibepredicted highweightage

8 Simple Harmonic Motion

embibepredicted highweightage

9 Heat &Thermodynamics

embibepredicted highweightage

10 Heat &Thermodynamics

embibepredicted highweightage

11 Heat &Thermodynamics

embibepredicted highweightage

12 Simple Harmonic Motion

embibepredicted highweightage

13 Wave & Sound

embibepredicted highweightage

14 Electrostatics

embibepredicted highweightage

15 Electrostatics

embibepredicted highweightage

16 Electrostatics

embibepredicted highweightage

17 Electrostatics

embibepredicted highweightage

18 Electrostaticsembibe

predicted high

Page 5: Detailed Analysis of JEE Main 2015

weightage

19 Magnetism

embibepredicted highweightage

20 Magnetism

embibepredicted highweightage

21 Magnetism

embibepredicted highweightage

22 Magnetism

embibepredicted highweightage

23 Optics

embibepredicted highweightage

24 Optics

embibepredicted highweightage

25 Optics

embibepredicted highweightage

26 Optics

embibepredicted highweightage

27 Modern Physics

embibepredicted highweightage

28 Modern Physics

embibepredicted highweightage

29 Communication Systems

embibepredicted highweightage

30 Magnetism

embibepredicted highweightage

Page 6: Detailed Analysis of JEE Main 2015

31 s-Block elements and Hydrogen

embibepredicted LowWeightage

32 Solid State

embibepredictedLowWeightage

33 Atomic Structure

embibepredicted highweightage

34 Chemical Bonding

embibepredicted highweightage

35 Thermochemistry and thermodynamics

embibepredicted highweightage

36 Liquid solution

embibepredicted highweightage

37 Chemical Equilibrium

embibepredicted easyto score (MustDo)

38 Electrochemistry

embibepredicted highweightage

39 Chemical kinetics

embibepredicted highweightage

40 Surface chemistry

embibepredicted highweightage

41 Periodicity

embibepredictedLowWeightage

42 Metallurgy embibe

Page 7: Detailed Analysis of JEE Main 2015

predicted highweightage

43 s-Block elements and hydrogen

embibepredictedLowWeightage

44 s-Block elements and hydrogen

embibepredictedLowWeightage

45 group 15 - 18

embibepredicted highweightage

46 Transition metals

embibepredicted highweightage

47 group 15 - 18

embibepredicted highweightage

48 Coordination compounds

embibepredicted highweightage

49 Coodination compounds

embibepredicted highweightage

50 group 15 - 18

embibepredicted highweightage

51 Stoichiometry

embibepredicted highweightage

52General Organic Chemistry andIsomerism

embibepredicted highweightage

53 Hydrocarbons

embibepredicted easyto score

Page 8: Detailed Analysis of JEE Main 2015

(Must Do)

54 Alkyl and Aryl halides

embibepredicted highweightage

55 Aldehyde and Ketone

embibepredicted highweightage

56 Amines

embibepredictedLowWeightage

57 Polymers

embibepredicted easyto score(Must Do)

58 Biomolecules

embibepredicted easyto score(Must Do)

59 Chemistry in everyday life

embibepredicted easyto score(Must Do)

60 Salt Analysis

embibepredicted easyto score(Must Do)

61 Matrices

embibepredicted highweightage

62 Complex Number

embibepredicted highweightage

63 Quadratic Equation & Expression

embibepredicted highweightage

64 Matrices embibe

Page 9: Detailed Analysis of JEE Main 2015

predicted highweightage

65 Determinants

embibepredicted highweightage

66 Permutation & Combination

embibepredictedLowWeightage

67 Binomial Theorem

embibepredicted highweightage

68 Progression & Series

embibepredicted highweightage

69 Progression & Series

embibepredicted highweightage

70 Limit,Continuity & Differentiability

embibepredicted highweightage

71 Limit,Continuity & Differentiability

embibepredicted highweightage

72 Straight Lines

embibepredicted highweightage

73 Application of Derivatives

embibepredicted highweightage

74 Indefinite Integral

embibepredicted LowWeightage

75 Definite Integral

embibepredicted highweightage

76 Area under Curves embibe

Page 10: Detailed Analysis of JEE Main 2015

predicted highweightage

77 Differential Equation

embibepredicted easyto score(Must Do)

78 Straight lines

embibepredicted highweightage

79 Straight lines

embibepredicted highweightage

80 Circle

embibepredicted highweightage

81 Ellipse

embibepredicted highweightage

82 Parabola

embibepredicted highweightage

83 3 - D Geometry

embibepredicted highweightage

84 3 - D Geometry

embibepredicted highweightage

85 Vector Algebra

embibepredicted highweightage

86 Probability

embibepredicted highweightage

87 Statistics

embibepredicted easyto score (MustDo)

Page 11: Detailed Analysis of JEE Main 2015

88 Height & Distance

embibepredicted easyto score (MustDo)

89 Inverse Trigonometric Function

embibepredicted easyto score (MustDo)

90 Mathematical Reasoning

embibepredicted easyto score (MustDo)

Physics – 25 Questions From High weightage and 2 from Easy to Score – (90% from the topicsmentioned important by embibe.

Chemistry – 18 Questions From High weightage and 6 from Easy to Score – (80% from thetopics mentioned important by embibe.

Math– 23 Questions From High weightage and 5 from Easy to Score – (93.3% from the topicsmentioned important by embibe.

Page 12: Detailed Analysis of JEE Main 2015
Page 13: Detailed Analysis of JEE Main 2015

Category Expected Cutoff Score 2015

Common Merit List (CML) 112-117

Other Backward Class (OBC - NCL) 74-80

Scheduled Caste (SC) 53-59

Scheduled Tribe (ST) 46-50

Tricks for lengthy questions –

1. A complex number z is said to be unimodular if |z| = 1. suppose z and z are complex

numbers such that is unimodular and z is not unimodular. Then the point z lies on a:

(A) Circle of radius √2(B) Straight line parallel to x-axis.

(C) Straight line parallel to y-axis.

Page 14: Detailed Analysis of JEE Main 2015

(D) Circle of radius 2

Answer: (D)

Sol. – Put z = 0, as it is not unimodular, we can assume z = 0, so we will get as unimodular

which will give us |z | = 2. Hence Option (D) is correct.

2. The normal to the curve, x + 2xy − 3y = 0, at (1, 1):

(A) Meets the curve again in the fourth quadrant.

(B) Does not meet the curve again.

(C) Meets the curve again in the second quadrant.

(D) Meets the curve

again in the third quadrant.

Answer: (A)Its Pair of straight lines passing through origin.x + 3y = 0 or x − y = 0 so normal at (1,1) will meets the curve again in thefourth quadrant. (Draw Diagram).

3. The negation of ~s ∨ (~r ∧ s) is equivalent to:

(A) s ∧ r(B) s ∧∼ r(C) s ∧ (r ∧ ∼ s)(D) s ∨ (r ∨ ∼ s)Answer: (A)Consider it as Sets.

Page 15: Detailed Analysis of JEE Main 2015

S = (1, 2) …..(i)r = (2, 3)U = (1, 2, 3, 4)Draw the Venn Diagram.S = (3, 4) (negesion of s)r̅ = (1, 4) (negesion of r)(r̅ ∩ S) = 1

And S U (r̅ ∩ S) -(3, 4) U (1) = (1, 3, 4)And Compliment of (1, 3, 4) is (2) which is (s ∩ r). Hence Option (A) is correct.

4. If A = 1 2 22 1 −2a 2 b is a matrix satisfying the equation AA = 9I, where I is 3 × 3 identity

matrix, then the ordered pairs (a, b) is equal to:

(A) (−2,−1)(B) (2, −1)

Page 16: Detailed Analysis of JEE Main 2015

(C) (−2, 1)(D) (2, 1)Answer: (A)1 2 22 1 −22 1 22 1 22 −2 =

9 0 00 9 00 0 9Multiply first row of A [1 ,2,2] by last column of . We will get + 4 + 2 = 0Only option (A) satisfies it.

5. If m is the A.M. of two distinct real numbers ( , > 1) , are threegeometric means between , ℎ + 2 + equals.

(A) 4(B) 4(C) 4(D) 4Answer: (C)From Dimension Analysis (A) is incorrect as giving dimension of (length) the power 6. FromSymmetry (C) is the answer. Links.

6. Let O be the vertex and Q be any point on the parabola, = 8 . If the point P divides theline segment OQ internally in the ratio 1 : 3, then the locus of P is:

(A) = 2(B) =(C) =(D) = 2Answer: (A)

Page 17: Detailed Analysis of JEE Main 2015

Sol. Find any one point on the locus and substitute in answers. Like (4,2) is a point on the curveand (1,1/2) divides OQ in the ratio 1:3. Hence (1,1/2) will satisfy the options.

7. The equation of the plane containing the line 2 − 5 + = 3 ; + + 4 = 5, and parallelto the plane, + 3 + 6 = 1, is:

(A) 2 + 6 + 12 = −13(B) 2 + 6 + 12 = 13(C) + 3 + 6 = −7(D) + 3 + 6 = 7Solution (D) Let the plane be + 3 + 6 = ,

As it contains the common line of line 2 − 5 + = 3 ; + + 4 = 5, we can find any pointon the line and substitute it in the our plane and find the value of K.

Put z = 0, 2 − 5 = 3 ; + = 5We will get x =4 and y=1. Put (4, 1, 0) in + 3 + 6 = , you will get K=7.

Hence (D) is the Correct option.

8. The sum of coefficients of integral powers of x in the binomial expansion of 1 − 2√ is:

(A) (2 + 1)(B) (3 + 1)(C) (3 )(D) (3 − 1)Solution: (B)It’s an easy question but if it is not striking to you then you can do it by Simulation Technique.

Page 18: Detailed Analysis of JEE Main 2015

Put 50 as 2 in the question and options. The question will become

The sum of coefficients of integral powers of x in the binomial expansion of 1 − 2√x is:

(A) (2 + 1)(B) (3 + 1)(C) (3 )(D) (3 − 1)1 − 2√x = 1 - 4 √x + 4x.

Sum of integral powers of x would be 5. (1 + 4 )

Only Option B is correct.

9. Locus of the image of the point (2, 3) in the line (2x − 3y + 4) + k (x − 2y + 3) = 0, k ∈R, is a :

(A) Circle of radius √3(B) Straight line parallel to x-axis.

(C) Straight line parallel to y-axis.

(D) Circle of radius √2Solution: (D)The infinite lines (2x − 3y + 4) + k (x − 2y + 3) = 0, k ∈ R, are passing through (1,2) and willhave infinite images of (2,3), Obviously the locus would not be a straight line (Draw .theDiagram ). As one of the line passes through (2,3) and image of (2,3) in that line would be (2,3)

itself, therefore (2,3) would lie on the locus. And distance of (2,3) from (1,2) is √2 hence option(D) is correct.

Page 19: Detailed Analysis of JEE Main 2015