GTM 49 Key
GTM 49 Key
GTM 49 Key
CHEMISTRY
31 2 32 1 33 3 34 4 35 3
36 4 37 1 38 3 39 3 40 4
41 4 42 1 43 4 44 4 45 4
46 2 47 2 48 4 49 2 50 1
51 20.00 52 4.80 to 5.00 53 0.33 to 0.34 54 0.16 to 0.17 55 4.00
56 5.00 57 1.00 58 3.00 59 2.50 60 4
MATHEMATICS
61 3 62 4 63 1 64 1 65 1
66 2 67 1 68 4 69 3 70 2
71 1 72 3 73 4 74 3 75 2
76 4 77 4 78 2 79 3 80 4
81 7.00 82 1.00 83 3.00 84 78.00 85 18
86 4 87 2 88 10 89 130.00 90 2.00
Sri Chaitanya IIT Academy 26-08-2021_Sr.Super60 & ICON All_Jee-Main_GTM-49_Key & Sol’s
SOLUTIONS
PHYSICS
1. Use the formula for angular magnification.
2. Use the formula for fringe width D
d
3. T m 2
v N
4. Use 1 1
v2 N 2
2 x 10
5. and
x 100 2 90
90 90
So 45 cm
100 10 110
h
6. Since v is increasing in case (i), but is it is not changing in case (ii). Hence, in
mv
the first case de-Broglie wavelength will change, but it second case, it remain the same
N Pb 1
7.
N Ur 2
N Ur
2
N Pb
NUr 2
N0 3
2 1
3 2n
3
2n
2
3
n n n 2
2
3 t
n n 2
2 T
n 3 / 2
tT
n 2
8. Photons per area per second at a distance r are 5.00 1018 / 4 r 2 . Photons per second
entering the eye, radius R is then this times R 2 . Set this product equal to 500 per
second and solve for r. The result is [B].
9. The P-N junctions will conduct only when it is forward biased i.e. when – 5V is fed
to it, so it will conduct only for 3rd quarter part of signal shown and when it conducts
potential drop 5 volt will be across both the resistors, so output voltage across R 2 is
2.5 V.
V0 2.5V
10.
200 T T 20
R 2R
400 2T T 20
T 140C
11. BH Bcentre
0 Ni 4107 100 2
2r 2 0.1
4 10 4 T
12. Speed max 7 105 m / s
2 2
1 31 10 21
9.1 10 49 10 9.1 10 49 0.5 J
2
Given incident frequency 8 1014 Hz
From photoelectric equation k max h h 0
h 0 h k max
6.6 1034 8 1014 91 49 5 1023
6.6 8 1020 91 49 5 1023
1021 66 8 91 49 5 102
528 223 1021 6.6 1034 0
305 30.5
0 1021 1034 1014 0
6.6 6.6
4.64 1014 Hz
k
13. As we know,
I
3k 1
2
I rod m 2
m 3
Velocity in medium C
2
Here, 1 2 1 as medium is non-magnetic
1
r1 C r1 1
2
1 C r2 4
r 2
2
21.
q1 max 1 6 6
q 2 max 2 4 8
q q1 max , q 2 max
q6
q 6
V 9 KV
Ceq 2
3
I
22. T 2
B
23. Pv nRT
2 P / nT Constant
P2 / n 2T2 P1 / n1T1
P2 P2 n 2 T2 / n1T1
If initial no of moles = 1 final no of moles = 0.5
T1 27C 273 27 300 k
T2 300 50 350 k
put in above eq n
P2 20 0.5 350 / 1 300
11.66 atm
h
24. r
2
, d 2r
r d 1
8V VCE
8V 4V 4V
Now IC R L 4V
4
RL 103 1k
4 103
26. Given : Radius of capillary tube, r 0.015 cm 15 10 5 mm
h 15 cm 15 10 2 mm
2T cos
Using, h cos cos 0 1
gr
rhg 15 105 15 102 900 10
Surface tension, T 101 milli newton m 1
2 2
27. Given,
Distance between an object and screen, D = 100 cm
Distance between the two position of lens, d = 40 cm
Focal length of lens,
Power, P 1 100 N
f 21 100
N 476.19 .
28.
CHEMISTRY
31. Stability of carbocation Aromatic > non aromatic > Anti aromatic
32.
H
H2 O
O Et O Et O Et O C2 H 5OH 2
C2 H 5OH H
34.
35. Electron with drawing groups increases reactivity but electron donating groups
decreases reactivity
36. -Keto acids undergo decarboxylation simply by heating.
37. In basic medium O is stronger donar than NH 2
38. Acidic amino acids will have low Isoelectric points. at pH=7 it exists as anion
39.
2
2
MATHEMATICS
61. Ans: 3
cos x sin x
Sol: dx
8 sin 2x
cos x sin x
dx
2
9 sin x cos x
Let sin x cos x t
dt 1 t
9 t 2 sin 3 c
sin x cos x
sin 1 c
3
So a = 1, b = 3.
62. Ans: 4
Sol: (i) 2 i z 2 i z
x
y
2
(ii) 2 i z i z z 4i 0
x 2y 2
(iii) iz z 1 i 0
Equation of tangent x y 1 0
Solving (i) and (ii)
1
x 1, y
2
1
1 1
Now, p r 2 r
2
1 n 1 1
lim
n n
2
r 0 r / n 2 r / n 1
1 1
dx 1 1
2
0 x 1 x 1 0 2
64. Ans: 1
2 7 12 17
Sol: S 1 ....
3 32 33 34
S 1 2 7 12 17
....
3 3 32 33 34 35
2S 1 5 5 5
1 2 3 4 ....
3 3 3 3 3
13
S
4
65. Ans: 1
Sol:
6
sin 30 x 12
x
66. Ans: 2
10!
Sol: Total number of arrangements =
3!2!
The number of arrangements in which two
9!
L’s appear adjacently =
3!
Total number of arrangements
10! 9!
3!2! 3!
69. Ans: 3
D 0 m2 3
m , 3 3, ……(1)
b
1 2 m 1,2 ……(2)
2a
f 1 0 m 2 and f 2 0
7
m ……(3)
4
7
from (1), (2), (3) m 3,
4
70. Ans: 2
6x 8 5x 6 3x 2
Sol: dx
x6 x4 1
1 12x11 10x 9 6x 5
dx
2 x12 x10 x 6
1
2
2 x12 x10 x 6 c
x3 x 6 x 4 1 c
p q pq p ~ q p q p ~ q ~ pq
(1) (2) pq
(1) (2)
T T T T T T T T
T F F T T F F F
F T F F F T F F
F F F T T T T T
72. Ans: 3
Sol: A,A R because it is not necessary that each matrix is inverse of itself.
Let A,A R A & B are inverse of each other.
AB I BA
BA AB B,A R
Now Let A, B R AB I BA ….. (1)
B,C R BC I CB …..(2)
From (1) & (2) (AB) (BC) = I
AB2C I
It is clear that AB2C I is AC I if, B2 I
which not possible of each matrix.
73. Ans: 4
Sol: x 6 6x 8 is non differentiable at x = 2, 4
at x = 2,
at x = 2, sin x 2 0
x 4sin x 2 0
So x 2 6x 8 sin x 2 is differentiable everywhere
Similarly, ex 1 sin x is differentiable every where and x 2 is differentiable
everywhere
74. Ans: 3
1
8
1 cos x 5x dx
1 5
Sol:
8
1
8
2I 1 dx I
8
8
75. Ans: 2
Sol: Let A = (2, 3, 4) and B = (5, 6, 7).
Then AB = 3 3 .
Sec: Sr.Super-60 & All Page 13
Sri Chaitanya IIT Academy 26-08-2021_Sr.Super60 & ICON All_Jee-Main_GTM-49_Key & Sol’s
Plane : 2x + y + z = 1
Projection of AB on vector 2iˆ ˆj kˆ which is normal to plane.
Normal to plane,
B
3iˆ 3jˆ 3kˆ . 2iˆ ˆj kˆ
12
2 6
6 6
Projection of AB on plane,
2 2
AC 3 3 2 6 3
76. Ans: 4
Sol: Area of parallelogram formed by line y m1x c1 , y m1x c 2 , y m 2 x d1 ,
y m 2 x d 2 is given by
Area of parallelogram = 1 2
c c d1 d 2
m1 m 2
x 5 x 15 c
For the given lines y ; y and y 3x 10; y 3x ,
2 2 2 2 2
c
5. 10
2
Area of parallelogram = 1
5
2
(Given)
c 20 1 21 or c 19
77. Ans: 4
Sol: Image of 2 ,2 in the line mirror x y 1 0 is
2
h 2 k 2 2 2 1
1 1 2
h 1 2 …….(1)
and k 2 1 ……(2)
2
h 1
Putting value of from (1) and (2), we get k 1
2
2
or 4 y 1 x 1 , which is the required locus
78. Ans: 2
1
1 r 1 r
Sol: Tr tan 1 2 tan tan 1
1 r r 1 2 2
2 2
1
S tan 1
2 2
79. Ans: 3
Sol: Normal vector:
ˆi ˆj kˆ
3 1 2 11iˆ ˆj 17kˆ
2 5 1
So drs of normal to the required plane is <11, 1, 17>
Plane passes through (1, 2, -3)
So equation of plane :
11 x 1 1 y 2 17 z 3 0
11x y 17z 38 0
80. Key 4
3 2 k
Sol: 2 4 2 0
1 2 1
24 2 0 k 8 0 k 3
10 2 3
x 6 4 2
5m 2 1
10 8 2 10m 6 312 20m
Sec: Sr.Super-60 & All Page 15
Sri Chaitanya IIT Academy 26-08-2021_Sr.Super60 & ICON All_Jee-Main_GTM-49_Key & Sol’s
8 4 5m
3 10 3
y 2 6 2
1 5m 1
3 6 10m 10 0 3 10m 6
=0
3 2 10
z 2 4 6
1 2 5m
3 20m 12 2 6 10m 10 8
40m 32 8 5m 4
For inconsistent
4
k 2&m
5
81. Ans: 7.00
2
Sol: Parabola is x 2 8 y 1
1
Now equation of normal having slope is
2
1 2
y 1 x 2 4
2 1 / 4
x 2y 28
82 Ans: 1.00
2 2 4k 2 36k 2 9k 2
2
k 16k 81k 2 21
2 2 2
1
147k 2 21 k
7
3
c 3k [magnitude is always +ve]
7
84. Ans: 78.00
A 5 3,7 , 2
B 3 3,3 2,6 4
direction of
AB 2 3 3, 4 2, 8 4
AB is perpendicular to L 2
11 29 18 0 …..(1)
2 3 3 4 2 8 4
Also
2 7 5
m 2 0 …..(2)
from (1) and (2) 1
1
A(2,8, -3) and B(0, 1, 2)
2
AB 4 49 25 78
85. Ans: 18
f x
4t 3dt
6 0
Sol: lim form
x 2 x 2 0
D’L rule
3
4 f x f ' x 0
lim
x 2 1
1
4.63 18
48
86. Ans: 4
1 9 1 1
Sol: 1 n n
2 10 10 2
n
2 10 n = 4
87. Ans: 2
Sec: Sr.Super-60 & All Page 17
Sri Chaitanya IIT Academy 26-08-2021_Sr.Super60 & ICON All_Jee-Main_GTM-49_Key & Sol’s
2
Sol: 2 2 2
2
3 2 2
2 9 6 4 2
2 4 5 For least value 2
88. Ans: 10
5
Sol: 4x 2 9x 5 0 x 1,
4
5 t t
Now given p q , t t p t q where
4 2
1
r 1
5 1 p1 1 q 1
t r 16 so 8
2 4 2 2
pq 2
1 pq2 8
1 256 2 pq2 1 2
2
hence p + q = 10
89. Ans: 130.00
P(B) = 1 if the event ‘A’ occurs atleast twice
P(B) = 0 if the event ‘A’ does not occurs
1
P(B) = if ‘A’ occurs once
2
3 2 2 3 1 4
4 1 2 1 4 1 2 4 1 2 4 1
P B C1 C2 C3 C4 1
3 3 2 3 3 3 3 3
49
=
81
90. Ans: 2.00
3 10 10 4 7 10 5
Sol: x 7
7
xi d1 x i x
3 4
10 3
10 3
4 3
7 0
10 3
5 2
18
18
MD 2.57
7