JEE Main 2018 (08 Apr) JEE Main Previous Year Paper
Question Paper MathonGo
Q1. The density of a material, in the shape of a cube, is determined by measuring three sides of the cube and its
mass. If the relative errors in measuring the mass and length are 1. 5% and 1%, respectively, the maximum error
in determining the density is:
(1) 6 % (2) 2.5 %
(3) 3.5 % (4) 4.5 %
Q2. All the graphs below are intended to represent the same motion. One of them does it incorrectly. Pick it up.
(1) (2)
(3) (4)
Q3. Two masses m 1 = 5 kg and m 2 , connected by an inextensible string over a frictionless pulley, are
= 10 kg
moving as shown in the figure. The coefficient of friction of horizontal surface is 0. 15. The minimum weight m
that should be put on top of m to stop the motion is:
2
(1) 10 .3 kg (2) 18 .3 kg
(3) 27 .3 kg (4) 43 .3 kg
Q4. A particle is moving in a circular path of radius a under the action of an attractive potential U = −
k
2r
2
. Its total
energy is:
(1) − 3
2
k
a
2
(2) – 4a
k
2
(3) k
2a
2
(4) Zero
Q5. In a collinear collision, a particle with an initial speed v strikes a stationary particle of the same mass. If the
0
final total kinetic energy is 50% greater than the original kinetic energy, the magnitude of the relative velocity
between the two particles, after the collision, is
(1) v0
√2
(2) v0
4
(3) √ 2 v
0 (4) v0
2
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, JEE Main 2018 (08 Apr) JEE Main Previous Year Paper
Question Paper MathonGo
Q6. It is found that if a neutron suffers an elastic collinear collision with a deuterium at rest, the fractional loss of its
energy is P , while for its similar collision with a carbon nucleus at rest, the fractional loss of energy is P . The
d c
values of P and P are respectively
d c
(1) 0, 1 (2) 0. 89, 0. 28
(3) 0. 28, 0. 89 (4) 0, 0
Q7. The mass of a hydrogen molecule is 3.32 × 10 −27
kg. If 10 23
hydrogen molecules strike, per second, a fixed
wall of the area 2 cm
2
at an angle of 45 to the normal, and rebound elastically with a speed of 10
o 3
m s
−1
, then
the pressure on the wall is nearly:
(1) 4.70 × 10 2
N m
−2
(2) 2.35 × 10 3
N m
−2
(3) 4.70 × 10 3
N m
−2
(4) 2.35 × 10 2
N m
−2
Q8. Seven identical circular planar disks, each of mass M and radius R are welded symmetrically as shown. The
moment of inertia of the arrangement about the axis normal to the plane and passing through the point P is:
(1) 181
2
MR
2
(2) 19
2
MR
2
(3) 55
2
MR
2
(4) 73
2
MR
2
Q9. From a uniform circular disc of radius R and mass 9 M, a small disc of radius R
3
is removed as shown in the
figure. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and
passing through centre of disc is:
(1) 37
9
MR
2
(2) 4M R 2
(3) 40
9
MR
2
(4) 10M R 2
Q10. A particle is moving with a uniform speed in a circular orbit of radius R in a central force inversely
proportional to the n th
power of R. If the period of rotation of the particle is T, then:
(1) T ∝ R
n/2
(2) T ∝ R
3/2
for any n
n n+1
(3) T ∝ R 2
+1
(4) T ∝ R 2
Q11. A solid sphere of radius r made of a soft material of bulk modulus K is surrounded by a liquid in a cylindrical
container. A massless piston of area a floats on the surface of the liquid, covering entire cross-section of
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Question Paper MathonGo
Q1. The density of a material, in the shape of a cube, is determined by measuring three sides of the cube and its
mass. If the relative errors in measuring the mass and length are 1. 5% and 1%, respectively, the maximum error
in determining the density is:
(1) 6 % (2) 2.5 %
(3) 3.5 % (4) 4.5 %
Q2. All the graphs below are intended to represent the same motion. One of them does it incorrectly. Pick it up.
(1) (2)
(3) (4)
Q3. Two masses m 1 = 5 kg and m 2 , connected by an inextensible string over a frictionless pulley, are
= 10 kg
moving as shown in the figure. The coefficient of friction of horizontal surface is 0. 15. The minimum weight m
that should be put on top of m to stop the motion is:
2
(1) 10 .3 kg (2) 18 .3 kg
(3) 27 .3 kg (4) 43 .3 kg
Q4. A particle is moving in a circular path of radius a under the action of an attractive potential U = −
k
2r
2
. Its total
energy is:
(1) − 3
2
k
a
2
(2) – 4a
k
2
(3) k
2a
2
(4) Zero
Q5. In a collinear collision, a particle with an initial speed v strikes a stationary particle of the same mass. If the
0
final total kinetic energy is 50% greater than the original kinetic energy, the magnitude of the relative velocity
between the two particles, after the collision, is
(1) v0
√2
(2) v0
4
(3) √ 2 v
0 (4) v0
2
Join the Most Relevant Test Series for JEE Main with Most Detailed & Advanced Analysis here: https://links.mathongo.com/mWN
, JEE Main 2018 (08 Apr) JEE Main Previous Year Paper
Question Paper MathonGo
Q6. It is found that if a neutron suffers an elastic collinear collision with a deuterium at rest, the fractional loss of its
energy is P , while for its similar collision with a carbon nucleus at rest, the fractional loss of energy is P . The
d c
values of P and P are respectively
d c
(1) 0, 1 (2) 0. 89, 0. 28
(3) 0. 28, 0. 89 (4) 0, 0
Q7. The mass of a hydrogen molecule is 3.32 × 10 −27
kg. If 10 23
hydrogen molecules strike, per second, a fixed
wall of the area 2 cm
2
at an angle of 45 to the normal, and rebound elastically with a speed of 10
o 3
m s
−1
, then
the pressure on the wall is nearly:
(1) 4.70 × 10 2
N m
−2
(2) 2.35 × 10 3
N m
−2
(3) 4.70 × 10 3
N m
−2
(4) 2.35 × 10 2
N m
−2
Q8. Seven identical circular planar disks, each of mass M and radius R are welded symmetrically as shown. The
moment of inertia of the arrangement about the axis normal to the plane and passing through the point P is:
(1) 181
2
MR
2
(2) 19
2
MR
2
(3) 55
2
MR
2
(4) 73
2
MR
2
Q9. From a uniform circular disc of radius R and mass 9 M, a small disc of radius R
3
is removed as shown in the
figure. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and
passing through centre of disc is:
(1) 37
9
MR
2
(2) 4M R 2
(3) 40
9
MR
2
(4) 10M R 2
Q10. A particle is moving with a uniform speed in a circular orbit of radius R in a central force inversely
proportional to the n th
power of R. If the period of rotation of the particle is T, then:
(1) T ∝ R
n/2
(2) T ∝ R
3/2
for any n
n n+1
(3) T ∝ R 2
+1
(4) T ∝ R 2
Q11. A solid sphere of radius r made of a soft material of bulk modulus K is surrounded by a liquid in a cylindrical
container. A massless piston of area a floats on the surface of the liquid, covering entire cross-section of
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