| Re: IIT JEE Physics Question Paper
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I am hereby providing you with the questions :
PART- I (PHYSICS)
SECTION – I
Straight Objective Type
This section contains 9 multiple choice questions numbered 1 to 9. Each question has 4 choices (A), (B), (C) and (D), out of
which only one is correct.
1. A circuit is connected as shown in the figure with the switch S open. When the
switch is closed the total amount of charge that flows from Y to X is
(A) 0 (B) 54µC
(C) 27 µC (D) 81 µC
S
X
Y
9V
3Ω 6Ω
3µF 6µF
Sol. (C)
27 µC
S
X
Y
9V
3Ω 6Ω
3µF 6µF
+18µC +18µC
1A
S
X
Y
9V
3µF 6µF
+9µC +36µC
+9µC +18µC
3Ω 6Ω
+27µC
Initial charge distribution (when switch S is open) Final charge distribution (when switch S is closed)
2. A long, hollow conducting cylinder is kept coaxially inside another long, hollow conducting cylinder of larger radius.
Both the cylinders are initially electrically neutral.
(A) A potential difference appears between the two cylinders when a charge density is given to the inner cylinder.
(B) A potential difference appears between the two cylinders when a charge density is given to the outer cylinder.
(C) No potential difference appears between the two cylinders when a uniform line charge is kept along the axis of the
cylinders.
(D) No potential difference appears between the two cylinders when same charge density is given to both the
cylinders.
Sol. (A)
dV E dr = − ⋅
and
0
E
2 r
λ
=
πε
where r is distance from the axis of cylindrical charge distribution (r is equal to or greater than radius of cylindrical
charge distribution).
3. In the options given below, let E denote the rest mass energy of a nucleus and n a neutron. The correct option is
(A) ( ) ( ) ( ) 236 137 97
92 53 39 E U E I E Y 2E(n) > + + (B) ( ) ( ) ( ) 236 137 97
92 53 39 E U E I E Y 2E(n) < + +
(C) ( ) ( ) ( ) 236 140 94
92 56 36 E U E Ba E Kr 2E(n) < + + (D) ( ) ( ) ( ) 236 140 94
92 56 36 E U E Ba E Kr 2E(n) = + +
3. (A)
Rest mass energy of U will be greater than the rest mass energy of the nucleus in which it breaks (as conservation of
momentum is always followed)
4. In an experiment to determine the focal length (f) of a concave mirror by the u–v method, a student places the object
pin A on the principal axis at a distance x from the pole P. The student looks at the pin and its inverted image from a
distance keeping his/her eye in line with PA. When the student shifts his/her eye towards left, the image appears to the
right of the object pin. Then,
(A) x < f (B) f < x < 2f
(C) x = 2f (D) x > 2f
Sol. (B)
Due to parallax
5. The largest wavelength in the ultraviolet region of the hydrogen spectrum is 122 nm. The smallest wavelength in the
infrared region of the hydrogen spectrum (to the nearest integer) is
(A) 802 nm (B) 823 nm
(C) 1882 nm (D) 1648 nm
Sol. (B)
Transition from ∞ to n = 3 will produce smallest wavelength in infrared region.
6. A resistance of 2 Ω is connected across one gap of a metre-bridge (the length of the wire is 100 cm) and an unknown
resistance, greater than 2Ω, is connected across the other gap. When these resistance are interchanged, the balance point
shifts by 20 cm. Neglecting any corrections, the unknown resistance is
(A) 3 Ω (B) 4 Ω
(C) 5 Ω (D) 6 Ω
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Sol. (A)
2
x 100
=
−
…(i)
x 20
2 80
+
=
−
…(ii)
Solving (i) and (ii) x = 3Ω
G
2 x
100−
7. A ray of light travelling in water is incident on its surface open to air. The angle of incidence is θ, which is less than the
critical angle. Then there will be
(A) only a reflected ray and no refracted ray
(B) only a refracted ray and no reflected ray
(C) a reflected ray and a refracted ray and the angle between them would be less than 180° − 2θ
(D) a reflected ray and a refracted ray and the angle between them would be greater than 180° − 2θ
Sol. (C)
air
water
Reflected ray
Incident ray
Refracted ray θ
θ θ
8. Two particle of mass m each are tied at the ends of a light string of length 2a. The
whole system is kept on a frictionless horizontal surface with the string held tight so
that each mass is at a distance ‘a’ from the center P (as shown in the figure). Now, the
mid-point of the string is pulled vertically upwards with a small but constant force F. As
a result, the particles move towards each other on the surface. The magnitude of
acceleration, when the separation between them becomes 2x is
F
P
m m
a a
(A)
2 2
F a
2m a x −
(B)
2 2
F x
2m a x −
(C)
F x
2m a
(D)
2 2 F a x
2m x
−
Sol. (B)
2T sin θ = F
T cos θ = mA
F 2 tan
mA
θ =
2 2
F x A
2m a x
= −
P
m
x
mg
N
θ
a T T
F
9. Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the
sphere is then,
(A) negative and distributed uniformly over the surface of the sphere
(B) negative and appears only at the point on the sphere closest to the point charge
(C) negative and distributed non-uniformly over the entire surface of the sphere
(D) zero
Sol. (D)
SECTION – II
Assertion - Reason Type
This section contains 4 questions numbered 10 to 13. Each question contains STATEMENT-1 (Assertion) and STATEMENT-2
(Reason). Each question has 4 choices (A), (B), (C) and (D) out of which ONLY ONE is correct.
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10. STATEMENT-1
The formula connecting u, v and f for a spherical mirror is valid only for mirrors whose sizes are very small compared
to their radii of curvature.
because
STATEMENT-2
Laws of reflection are strictly valid for plane surfaces, but not for large spherical surfaces.
(A) Statement-1 is True, Statement-2 is True; Statement -2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement -2 is NOT a correct explanation for Statement-1.
(C) Statement -1 is True, Statement-2 is False.
(D) Statement -1 is False, Statement-2 is True.
Sol. (C)
11. STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-rays do not change.
because
STATEMENT -2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.
(A) Statement-1 is True, Statement-2 is True; Statement -2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement -2 is NOT a correct explanation for Statement-1.
(C) Statement -1 is True, Statement-2 is False.
(D) Statement -1 is False, Statement-2 is True.
Sol. (B)
12. STATEMENT-1
A block of mass m starts moving on a rough horizontal surface with a velocity v. It stops due to friction between the
block and the surface after moving through a certain distance. The surface is now tilted to an angle of 300 with the
horizontal and the same block is made to go up on the surface with the same initial velocity v. The decrease in the
mechanical energy in the second situation is smaller than that in the first situation.
because
STATEMENT-2
The coefficient of friction between the block and the surface decreases with the increase in the angle of inclination.
(A) Statement -1 is True, Statement-2 is True; Statement-2 is a correct explanation for statement-1.
(B) Statement -1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for statement-1.
(C) Statement -1 is True, Statement-2 is False.
(D) Statement -1 is False, Statement-2 is True.
Sol. (C)
13. STATEMENT-1
In an elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed
before the collision.
because
STATEMENT-2
In an elastic collision, the linear momentum of the system is conserved.
(A) Statement -1 is True, Statement-2 is True; Statement -2 is a correct explanation for Statement-1.
(B) Statement -1 is True, Statement-2 is True; Statement -2 is NOT a correct explanation for Statement-1.
(C) Statement -1 is True, Statement-2 is False.
(D) Statement -1 is False, Statement-2 is True.
Sol. (B)
SECTION – III
Linked Comprehension Type
This section contains 2 paragraphs P14-16 and P17-19. Based upon each paragraph, 3 multiple choice questions have to be
answered. Each question has 4 choices (A), (B), (C) and (D), out of which ONLY ONE is correct.
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P14 – 16 : Paragraph for Question Nos. 14 to 16
A fixed thermally conducting cylinder has a radius R and height L0. The cylinder is open
at its bottom and has a small hole at its top. A piston of mass M is held at a distance L
from the top surface, as shown in the figure. The atmospheric pressure is P0.
14. The piston is now pulled out slowly and held at a distance 2L from the top.
The pressure in the cylinder between its top and the piston will then be
(A) P0 (B) 0 P
2
(C) 0
2
P Mg
2 R
+
π
(D) 0
2
P Mg
2 R
−
π
2R
L0
L
Piston
Sol. (A)
15. While the piston is at a distance 2L from the top, the hole at the top is sealed. The piston is then released, to a position
where it can stay in equilibrium. In this condition, the distance of the piston from the top is
(A) ( )
2
0
2
0
2P R 2L
R P Mg
π
π +
(B) ( )
2
0
2
0
P R Mg 2L
R P
π −
π
(C) ( )
2
0
2
0
P R Mg 2L
R P
π +
π
(D) ( )
2
0
2
0
P R 2L
R P Mg
π
π −
Sol. (D)
Mg + P(πR2) = P0πR2
P0(2LπR2) = P(xπR2) (P1`V1 = P2V2 for isothermal process)
x = ( )
2
0
2
0
P R 2L
R P Mg
π
π −
16. The piston is taken completely out of the cylinder. The hole at the top is sealed. A
water tank is brought below the cylinder and put in a position so that the water surface
in the tank is at the same level as the top of the cylinder as shown in the figure. The
density of the water is ρ. In equilibrium, the height H of the water column in the
cylinder satisfies
(A) ρg(L0−H)2 + P0(L0 − H) + L0P0 = 0
(B) ρg(L0−H)2 − P0(L0 − H) − L0P0 = 0
(C) ρg(L0−H)2 + P0(L0 − H) − L0P0 = 0
(D) ρg(L0−H)2 − P0(L0 − H) + L0P0 = 0
H
L0
Sol. (C)
πR2P0L0 = P(L0 − H)πR2 . . . (i)
P = P0 + ρg(L0 − H) . . . (ii)
Solving (i) & (ii), we get the answer.
P17 – 19 : Paragraph for Question Nos. 17 to 19
Two discs A and B are mounted coaxially on a vertical axle. The discs have moments of inertia I and 2I respectively about the
common axis. Disc A is imparted an initial angular velocity 2 ω using the entire potential energy of a spring compressed by a
distance x1. Disc B is imparted an angular velocity ω by a spring having the same spring constant and compressed by a distance
x2. Both the discs rotate in the clockwise direction.
17. The ratio of x1/x2 is
(A) 2 (B) 1
2
(C) 2 (D) 1
2
Sol. (C)
( )2 2
1
1 1 kx I 2
2 2
= ω
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( )( )2 22
1 1 kx 2I
2 2
= ω
1
2
x 2
x
=
18. When disc B is brought in contact with disc A, they acquire a common angular velocity in time t. The average frictional
torque on one disc by the other during this period is
(A) 2I
3t
ω
(B) 9I
2t
ω
(C) 9I
4t
ω
(D) 3I
2t
ω
Sol. (A)
Applying conservation of angular momentum
( ) ( ) I 2 2I 4
3I 3
ω + ω ω ′ ω = = . . . (i)
t
2I
τ ′ ω = ω + . . . (ii)
From (1) & (ii), τ = 2I
3t
ω
19. The loss of kinetic energy during the above process is
(A)
2 I
2
ω
(B)
2 I
3
ω
(C)
2 I
4
ω
(D)
2 I
6
ω
Sol. (B)
SECTION – IV
Matrix-Match Type
This section contains 3 questions. Each question contains statements given in two columns which have to be matched. Statements
(A, B, C, D) in column I have to be matched with statements (p, q, r, s) in column II. The answers to these questions have to be
appropriately bubbled as illustrated in the following example.
If the correct match are A-p, A-s, B-r, C-p, C-q and D-s, then the correctly bubbled 4 × 4 matrix should be as follows:
p q r s
p q r s
p q r s
p q r s
p q r s
D
C
B
A
20. Some physical quantities are given in Column I and some possible SI units in which these quantities may be expressed
are given in Column II. Match the physical quantities in Column I with the units in Column II and indicate your
answer by darkening appropriate bubbles in the 4 × 4 matrix given in the ORS.
Column I Column II
(A) e s GM M
G → universal gravitational constant, e M → mass of the earth,
s M → mass of the Sun
(p) (volt) (coulomb) (metre)
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(B)
3RT
M
; R → universal gas constant, T → absolute temperature,
M → molar mass
(q) (kilogram) (metre)3 (second)−2
(C)
2
2 2
F
q B
; F → force, q → charge, B → magnetic field
(r) (meter)2 (second)−2
(D) e
e
GM
R
, G → universal gravitational constant,
e M → mass of the earth, e R → radius of the earth
(s) (farad) (volt)2 (kg)−1
Sol. A →(p) & (q), B →(r) & (s), C →(r) & (s), D →(r) & (s)
21. Some laws/processes are given in Column I. Match these with the physical phenomena given in Column II and
indicate your answer by darkening appropriate bubbles in the 4 × 4 matrix given in the ORS.
Column I Column II
(A) Transition between two atomic energy levels (p) Characteristic X-rays
(B) Electron emission from a material (q) Photoelectric effect
(C) Mosley’s law (r) Hydrogen spectrum
(D) Change of photon energy into kinetic energy of electrons (s) β-decay
Sol. A →(p) & (r), B →(q) & (s), C →(p), D →(q)
22. (C)olumn I gives certain situations in which a straight metallic wire of resistance R is used and Column II gives some
resulting effects. Match the statements in Column I with the statements in Column II and indicate your answer by
darkening appropriate bubbles in the 4 × 4 matrix given in the ORS.
Column I Column II
(A) A charged capacitor is connected to the ends of the wire (p) A constant current flows through the wire
(B) The wire is moved perpendicular to its length with a constant
velocity in a uniform magnetic field perpendicular to the
plane of motion
(q) Thermal energy is generated in the wire
(C) The wire is placed in a constant electric field that has a
direction along the length of the wire.
(r) A constant potential difference develops
between the ends of the wire
(D) A battery of constant emf is connected to the ends of the wire (s) Charges of constant magnitude appear at
the ends of the wire
Sol. A →(q), B →(r) & (s), C →(r) & (s), D →(p), (q) & (r)
# Along with this I am providing you with the syllabus of physics:
1.General: Units and dimensions, dimensional analysis; least count, significant figures; Methods of measurement and error analysis for physical quantities pertaining to the following experiments: Experiments based on using vernier calipers and screw gauge (micrometer), Determination of g using simple pendulum, Young's modulus by Searle's method, Specific heat of a liquid using calorimeter, focal length of a concave mirror and a convex lens using u-v method, Speed of sound using resonance column, Verification of Ohm's law using voltmeter and ammeter, and specific resistance of the material of a wire using meter bridge and post office box.
2.Mechanics: Kinematics in one and two dimensions (Cartesian coordinates only), projectiles; Circular motion (uniform and non-uniform); Relative velocity.
3.Newton's laws of motion; Inertial and uniformly accelerated frames of reference; Static and dynamic friction; Kinetic and potential energy; Work and power; Conservation of linear momentum and mechanical energy.
4.Systems of particles; Centre of mass and its motion; Impulse; Elastic and inelastic collisions.
5.Law of gravitation; Gravitational potential and field; Acceleration due to gravity; Motion of planets and satellites in circular orbits.
6.Rigid body, moment of inertia, parallel and perpendicular axes theorems, moment of inertia of uniform bodies with simple geometrical shapes; Angular momentum; Torque; Conservation of angular momentum; Dynamics of rigid bodies with fixed axis of rotation; Rolling without slipping of rings, cylinders and spheres; Equilibrium of rigid bodies; Collision of point masses with rigid bodies.
7.Linear and angular simple harmonic motions.
.Hooke's law, Young's modulus.
.Pressure in a fluid; Pascal's law; Buoyancy; Surface energy and surface tension, capillary rise; Viscosity (Poiseuille's equation excluded), Stoke's law; Terminal velocity, Streamline flow, Equation of continuity, Bernoulli's theorem and its applications.
.Wave motion (plane waves only), longitudinal and transverse waves, Superposition of waves; progressive and stationary waves; Vibration of strings and air columns. Resonance; Beats; Speed of sound in gases; Doppler effect (in sound).
.Thermal physics: Thermal expansion of solids, liquids and gases; Calorimetry, latent heat; Heat conduction in one dimension; Elementary concepts of convection and radiation; Newton's law of cooling; Ideal gas laws; Specific heats (Cv and Cp for monatomic and diatomic gases); Isothermal and adiabatic processes, bulk modulus of gases; Equivalence of heat and work; First law of thermodynamics and its applications (only for ideal gases). Blackbody radiation: absorptive and emissive powers; Kirchhoff's law, Wien's displacement law, Stefan's law.
.Electricity and magnetism: Coulomb's law; Electric field and potential; Electrical Potential energy of a system of point charges and of electrical dipoles in a uniform electrostatic field, Electric field lines; Flux of electric field; Gauss's law and its application in simple cases, such as, to find field due to infinitely long straight wire, uniformly charged infinite plane sheet and uniformly charged thin spherical shell.
.Capacitance; Parallel plate capacitor with and without dielectrics; Capacitors in series and parallel; Energy stored in a capacitor.
.Electric current: Ohm's law; Series and parallel arrangements of resistances and cells; Kirchhoff's laws and simple applications; Heating effect of current.
.Biot-Savart law and Ampere's law, magnetic field near a current-carrying straight wire, along the axis of a circular coil and inside a long straight solenoid; Force on a moving charge and on a current-carrying wire in a uniform magnetic field.
.Magnetic moment of a current loop; Effect of a uniform magnetic field on a current loop; Moving coil galvanometer, voltmeter, ammeter and their conversions.
.Electromagnetic induction: Faraday's law, Lenz's law; Self and mutual inductance; RC, LR and LC circuits with d.c. and a.c. sources.
.Optics: Rectilinear propagation of light; Reflection and refraction at plane and spherical surfaces; Total internal reflection; Deviation and dispersion of light by a prism; Thin lenses; Combinations of mirrors and thin lenses; Magnification.
.Wave nature of light: Huygen's principle, interference limited to Young's double-slit experiment.
.Modern physics: Atomic nucleus; Alpha, beta and gamma radiations; Law of radioactive decay; Decay constant; Half-life and mean life; Binding energy and its calculation; Fission and fusion processes; Energy calculation in these processes.
.Photoelectric effect; Bohr's theory of hydrogen-like atoms; Characteristic and continuous X-rays, Moseley's law; de
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