JEE-MAIN SERIES
Physics

Quantum Mechanics

34 previous year questions.

Volume: 34 Ques
Yield: High

High-Yield Trend

28
2026
6
2025

Chapter Questions
34 MCQs

01
PYQ 2025
medium
physics ID: jee-main


Consider two blocks A and B of masses kg and kg that are placed on a frictionless table. The block A moves with a constant speed m/s towards the block B kept at rest. A spring with spring constant N/m is attached with the block B as shown in the figure. After the collision, suppose that the blocks A and B, along with the spring in constant compression state, move together, then the compression in the spring is, (Neglect the mass of the spring)

1
0.2 m
2
0.4 m
3
0.1 m
4
0.3 m
02
PYQ 2025
hard
physics ID: jee-main
An electron projected perpendicular to a uniform magnetic field moves in a circle. If Bohr’s quantization is applicable, then the radius of the electronic orbit in the first excited state is:
1

2

3

4

03
PYQ 2025
hard
physics ID: jee-main
An electron projected perpendicular to a uniform magnetic field moves in a circle. If Bohr’s quantization is applicable, then the radius of the electronic orbit in the first excited state is:
1

2

3

4

04
PYQ 2025
medium
physics ID: jee-main
A particle is released from height above the surface of the earth. At a certain height its K.E is 3 times of P.E. The height from the surface of the earth and the speed of the particle at the instant are respectively:
1

2

3

4

05
PYQ 2025
hard
physics ID: jee-main
A force of 49 N acts tangentially at the highest point of a sphere (solid of mass 20 kg) kept on a rough horizontal plane. If the sphere rolls without slipping, then the acceleration of the center of the sphere is:
1

2

3

4

06
PYQ 2025
hard
physics ID: jee-main
A satellite is launched into a circular orbit of radius around the earth. A second satellite is launched into an orbit of radius . The time period of revolution of the second satellite is larger than the first one approximately by:
1
3 %
2
4.5 %
3
9 %
4
2.5 %
07
PYQ 2026
medium
physics ID: jee-main
The de Broglie wavelength for an electron accelerated through the potential difference of volt is . When the potential difference is changed to volt, the associated de Broglie wavelength is increased by . If , then the value of is _____.
08
PYQ 2026
medium
physics ID: jee-main
An electron is travelling with a velocity in free space and when it enters a medium, its velocity is reduced by 20%. The de Broglie wavelength of electron in the medium is , where is its de Broglie wavelength in free space. The value of is \dots
1
1.20
2
1.0
3
1.25
4
0.75
09
PYQ 2026
hard
physics ID: jee-main

Find magnitude of acceleration of particle at . If velocity–time graph is given as shown in figure.

1

2

3

4
10
PYQ 2026
medium
physics ID: jee-main

1
Overall cell reaction:

2
Electrical work done by the cell = charge potential difference.
3
\frac(E - E₀)RT log Q
4
In the overall cell reaction, the number of electrons are not present, as electron liberated at anode, are consumed at cathode.
11
PYQ 2026
medium
physics ID: jee-main

Two strings with lengths and , and Young's moduli and are elongated under two weights as shown. Find the ratio .
Case (1): String has Young's modulus , length , cross–sectional area and a mass is attached.
Case (2): String has Young's modulus , length , cross–sectional area and a mass is attached.

1

2

3

4
12
PYQ 2026
medium
physics ID: jee-main
Two cars and are moving on a road with speeds and respectively. A stone is thrown from car with speed km/h relative to it. The stone hits car with speed relative to car (ignore gravity). Find .
1

2

3

4
13
PYQ 2026
hard
physics ID: jee-main

Consider a ring of radius which rotates about a horizontal axis as shown (axis is tangent to the ring). Find the time period of small oscillations.

1

2

3

4
14
PYQ 2026
medium
physics ID: jee-main
An electron of mass is moving in an electric field ( ), with an initial velocity ( ). If , its de Broglie wavelength at time is:
1
2
3
4

15
PYQ 2026
medium
physics ID: jee-main

If the rolling object reaches a maximum height , what may be the object?

1
Solid sphere
2
Ring
3
Disc
4
Hollow sphere
16
PYQ 2026
medium
physics ID: jee-main
A wheel initially at rest is subjected to a uniform angular acceleration about its axis. In the first sec it rotates through an angle and in the next sec it rotates an angle . Find the ratio .
1

2

3

4
17
PYQ 2026
medium
physics ID: jee-main

Friction is sufficient so that the block does not slide. Find the work done by friction in sec.

1

2

3

4
18
PYQ 2026
medium
physics ID: jee-main
A cylindrical container has radius 40 cm and volume 528 . It is placed on a table of same height as of container. A hole is made 70 cm below from the free surface. Find range of efflux on ground if the container is filled completely.
1

2

3
140 cm
4
280 cm
19
PYQ 2026
medium
physics ID: jee-main
When a mass of 200 gm hangs from the ceiling via spring in equilibrium, the extension in the spring is observed to be 2mm. Find angular frequency of its SHM and energy stored in equilibrium position respectively.
1

2

3

4

20
PYQ 2026
medium
physics ID: jee-main
Find magnetic field at mid point between two parallel infinite wires carrying current of 30 Amp as shown in the figure.
1
0 µT
2
300 µT
3
150 µT
4
30 µT
21
PYQ 2026
medium
physics ID: jee-main
C = 100 pF, V = 100 V (given spherical capacitor).
Identical capacitor is touched with this capacitor. If change in total energy is α × 10^-7 J then find α = ?
(Combined capacitance = 200 pF)
1
2.5
2
25
3
1
4
10
22
PYQ 2026
medium
physics ID: jee-main
On an incline plane of angle , time taken by an object is if it is smooth and if it is rough. Find value of if friction coefficient is .
23
PYQ 2026
hard
physics ID: jee-main

As shown in the figure, the ratio of and is

1

2

3

4
24
PYQ 2026
medium
physics ID: jee-main

Find ratio of potential energy of a body at point A to point B for the figure shown.

1

2

3

4
25
PYQ 2026
medium
physics ID: jee-main
Escape velocity on earth is . A planet has half the radius of earth and density equal to half that of earth. If escape speed from that planet is , find .
1

2

3

4
26
PYQ 2026
easy
physics ID: jee-main
A cube of side length having modulus of rigidity . The top is pulled by a force while the bottom is fixed. Find the displacement of the upper surface of cube (in mm).
27
PYQ 2026
medium
physics ID: jee-main
Two points and are from the surface of Earth. Point is above the surface while point is below the surface. Acceleration due to gravity at and are and respectively. Find . (Take radius of Earth )
1

2

3

4
28
PYQ 2026
medium
physics ID: jee-main
A ball is dropped from a height above the ground. At any moment, if magnitude of acceleration and velocity are same, find its height above ground at that instant.
1

2

3

4
29
PYQ 2026
medium
physics ID: jee-main

Find the ratio of and for the system shown.

1

2

3

4
30
PYQ 2026
medium
physics ID: jee-main

Upper wire has cross-section area and lower wire has area . Find the maximum mass of the pan that can be connected without breaking any wire. Given breaking stress of wire is .


1

2

3

4
31
PYQ 2026
medium
physics ID: jee-main

Find time taken by the block to slide a distance with respect to the wedge (in seconds). All surfaces are smooth.

1

2

3

4
32
PYQ 2026
medium
physics ID: jee-main
Moment of inertia of a rod about an axis passing through a point at distance from the center and perpendicular to the rod is: (The uniform rod has mass and length ).
1

2

3

4
33
PYQ 2026
medium
physics ID: jee-main
In a region where electric field exists as Initially at , velocity of particle of mass is . If de-Broglie wavelength , find wavelength at time .}
1

2

3

4
34
PYQ 2026
medium
physics ID: jee-main
If a metal rod has length and area of cross-section , its Young's modulus is . What will happen to if length is doubled and area is halved?
1
Becomes double
2
Becomes four times
3
Becomes halved
4
Remains same