JEE MAIN - Physics (2022 - 26th June Evening Shift)
1
The dimension of mutual inductance is :
Answer
(C)
$$[M{L^2}{T^{ - 2}}{A^{ - 2}}]$$
2
In the arrangement shown in figure a1, a2, a3 and a4 are the accelerations of masses m1, m2, m3 and m4 respectively. Which of the following relation is true for this arrangement?
Answer
(A)
4a1 + 2a2 + a3 + a4 = 0
3
Arrange the four graphs in descending order of total work done; where W1, W2, W3 and W4 are the work done corresponding to figure a, b, c and d respectively.
Answer
(A)
W3 > W2 > W1 > W4
4
A solid spherical ball is rolling on a frictionless horizontal plane surface about its axis of symmetry. The ratio of rotational kinetic energy of the ball to its total kinetic energy is
Answer
(B)
$${2 \over 7}$$
5
Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : If we move from poles to equator, the direction of acceleration due to gravity of earth always points towards the center of earth without any variation in its magnitude.
Reason R : At equator, the direction of acceleration due to the gravity is towards the center of earth.
In the light of above statements, choose the correct answer from the options given below:
Answer
(D)
A is false but R is true.
6
If p is the density and $$\eta$$ is coefficient of viscosity of fluid which flows with a speed v in the pipe of diameter d, the correct formula for Reynolds number Re is :
Answer
(C)
$${R_e} = {{\rho vd} \over \eta }$$
7
A flask contains argon and oxygen in the ratio of 3 : 2 in mass and the mixture is kept at 27$$^\circ$$C. The ratio of their average kinetic energy per molecule respectively will be :
Answer
(D)
1 : 1
8
The charge on capacitor of capacitance 15$$\mu$$F in the figure given below is :
Answer
(A)
60$$\mu$$c
9
A parallel plate capacitor with plate area A and plate separation d = 2 m has a capacitance of 4 $$\mu$$F. The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant K = 3 (as shown in figure) will be :
Answer
(C)
6$$\mu$$F
10
Sixty four conducting drops each of radius 0.02 m and each carrying a charge of 5 $$\mu$$C are combined to form a bigger drop. The ratio of surface density of bigger drop to the smaller drop will be :
Answer
(B)
4 : 1
11
The equivalent resistance between points A and B in the given network is :
Answer
(C)
5$$\Omega$$
12
A bar magnet having a magnetic moment of 2.0 $$\times$$ 105 JT$$-$$1, is placed along the direction of uniform magnetic field of magnitude B
= 14 $$\times$$ 10$$-$$5 T. The work done in rotating the magnet slowly through 60$$^\circ$$ from the direction of field is :
Answer
(A)
14 J
13
Two coils of self inductance L1 and L2 are connected in series combination having mutual inductance of the coils as M. The equivalent self inductance of the combination will be :
Answer
(D)
$${L_1} + {L_2} - 2M$$
14
A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity 5 rad s$$-$$1. If the horizontal component of earth's magnetic field is 0.2 $$\times$$ 10$$-$$4 T, then emf induced between the two ends of the conductor is :
Answer
(B)
50 $$\mu$$V
15
Which is the correct ascending order of wavelengths?
For a specific wavelength 670 nm of light coming from a galaxy moving with velocity v, the observed wavelength is 670.7 nm. The value of v is :
Answer
(C)
3.13 $$\times$$ 105 ms$$-$$1
17
A metal surface is illuminated by a radiation of wavelength 4500 $$\mathop A\limits^o $$. The ejected photo-electron enters a constant magnetic field of 2 mT making an angle of 90$$^\circ$$ with the magnetic field. If it starts revolving in a circular path of radius 2 mm, the work function of the metal is approximately :
Answer
(A)
1.36 eV
18
A ball is projected vertically upward with an initial velocity of 50 ms$$-$$1 at t = 0s. At t = 2s, another ball is projected vertically upward with same velocity. At t = __________ s, second ball will meet the first ball (g = 10 ms$$-$$2).
Answer
6
19
A batsman hits back a ball of mass 0.4 kg straight in the direction of the bowler without changing its initial speed of 15 ms$$-$$1. The impulse imparted to the ball is ___________ Ns.
Answer
12
20
A system to 10 balls each of mass 2 kg are connected via massless and unstretchable string. The system is allowed to slip over the edge of a smooth table as shown in figure. Tension on the string between the 7th and 8th ball is __________ N when 6th ball just leaves the table.
Answer
36
21
A geyser heats water flowing at a rate of 2.0 kg per minute from 30$$^\circ$$C to 70$$^\circ$$C. If geyser operates on a gas burner, the rate of combustion of fuel will be ___________ g min$$-$$1.
[Heat of combustion = 8 $$\times$$ 103 Jg$$-$$1, Specific heat of water = 4.2 Jg$$-$$1 $$^\circ$$C$$-$$1]
Answer
42
22
A set of 20 tuning forks is arranged in a series of increasing frequencies. If each fork gives 4 beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first, then the frequency of last fork is _________ Hz.
Answer
152
23
Two 10 cm long, straight wires, each carrying a current of 5A are kept parallel to each other. If each wire experienced a force of 10$$-$$5 N, then separation between the wires is ____________ cm.
Answer
5
24
A small bulb is placed at the bottom of a tank containing water to a depth of $$\sqrt7$$ m. The refractive index of water is $${4 \over 3}$$. The area of the surface of water through which light from the bulb can emerge out is x$$\pi$$ m2. The value of x is __________.
Answer
9
25
A travelling microscope is used to determine the refractive index of a glass slab. If 40 divisions are there in 1 cm on main scale and 50 Vernier scale divisions are equal to 49 main scale divisions, then least count of the travelling microscope is __________ $$\times$$ 10$$-$$6 m.
Answer
5
26
The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630 $$\mathop A\limits^o $$ is 0.42 V. If the threshold frequency is x $$\times$$ 1013 /s, where x is _________ (nearest integer).