JEE MAIN - Physics (2022 - 27th June Morning Shift)

1
A projectile is launched at an angle '$$\alpha$$' with the horizontal with a velocity 20 ms^$$-$$1. After 10 s, its inclination with horizontal is '$$\beta$$'. The value of tan$$\beta$$ will be : (g = 10 ms^$$-$$2).
คำตอบ
(B)
tan$$\alpha$$ $$-$$ 5sec$$\alpha$$
2
A girl standing on road holds her umbrella at 45$$^\circ$$ with the vertical to keep the rain away. If she starts running without umbrella with a speed of 15$$\sqrt2$$ kmh^$$-$$1, the rain drops hit her head vertically. The speed of rain drops with respect to the moving girl is :
คำตอบ
(C)
$${{30} \over {\sqrt 2 }}$$ kmh^$$-$$1
3
A silver wire has a mass (0.6 $$\pm$$ 0.006) g, radius (0.5 $$\pm$$ 0.005) mm and length (4 $$\pm$$ 0.04) cm. The maximum percentage error in the measurement of its density will be :
คำตอบ
(A)
4%
4
A system of two blocks of masses m = 2 kg and M = 8 kg is placed on a smooth table as shown in figure. The coefficient of static friction between two blocks is 0.5. The maximum horizontal force F that can be applied to the block of mass M so that the blocks move together will be :

คำตอบ
(C)
49 N
5
Two blocks of masses 10 kg and 30 kg are placed on the same straight line with coordinates (0, 0) cm and (x, 0) cm respectively. The block of 10 kg is moved on the same line through a distance of 6 cm towards the other block. The distance through which the block of 30 kg must be moved to keep the position of centre of mass of the system unchanged is :
คำตอบ
(C)
2 cm towards the 10 kg block
6
A 72 $$\Omega$$ galvanometer is shunted by a resistance of 8 $$\Omega$$. The percentage of the total current which passes through the galvanometer is :
คำตอบ
(B)
10%
7
Given below are two statements :

Statement I : The law of gravitation holds good for any pair of bodies in the universe.

Statement II : The weight of any person becomes zero when the person is at the centre of the earth.

In the light of the above statements, choose the correct answer from the options given below.
คำตอบ
(A)
Both Statement I and Statement II are true
8
What percentage of kinetic energy of a moving particle is transferred to a stationary particle when it strikes the stationary particle of 5 times its mass?

(Assume the collision to be head-on elastic collision)
คำตอบ
(C)
55.6%
9
The velocity of a small ball of mass 'm' and density d₁, when dropped in a container filled with glycerin, becomes constant after some time. If the density of glycerin is d₂, then the viscous force acting on the ball, will be :
คำตอบ
(B)
$$mg\left( {1 - {{{d_2}} \over {{d_1}}}} \right)$$
10
The susceptibility of a paramagnetic material is 99. The permeability of the material in Wb/A-m, is :

[Permeability of free space $$\mu$$₀ = 4$$\pi$$ $$\times$$ 10^$$-$$7 Wb/A-m]
คำตอบ
(C)
4$$\pi$$ $$\times$$ 10^$$-$$5
11
The current flowing through an ac circuit is given by

I = 5 sin(120$$\pi$$t)A

How long will the current take to reach the peak value starting from zero?
คำตอบ
(D)
$${1 \over {240}}$$ s

Match List-I with List-II :

	List - I		List - II
(a)	Ultraviolet rays	(i)	Study crystal structure
(b)	Microwaves	(ii)	Greenhouse effect
(c)	Infrared rays	(iii)	Sterilizing surgical instrument
(d)	X-rays	(iv)	Radar system

Choose the correct answer from the options given below :

คำตอบ

(A)

(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)

13
An $$\alpha$$ particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelengths $$({\lambda _\alpha }:{\lambda _{C12}})$$ is :
คำตอบ
(B)
$$\sqrt 3 :1$$
14
A force of 10 N acts on a charged particle placed between two plates of a charged capacitor. If one plate of capacitor is removed, then the force acting on that particle will be.
คำตอบ
(A)
5 N
15
The displacement of simple harmonic oscillator after 3 seconds starting from its mean position is equal to half of its amplitude. The time period of harmonic motion is :
คำตอบ
(D)
36 s
16
Consider a light ray travelling in air is incident into a medium of refractive index $$\sqrt{2n}$$. The incident angle is twice that of refracting angle. Then, the angle of incidence will be :
คำตอบ
(D)
$$2{\cos ^{ - 1}}\left( {\sqrt {{n \over 2}} } \right)$$
17
A hydrogen atom in its ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen atom will increase by the value of :

(Given, Planck's constant = 6.6 $$\times$$ 10^$$-$$34 Js).
คำตอบ
(B)
1.05 $$\times$$ 10^$$-$$34 Js
18
Identify the correct Logic Gate for the following output (Y) of two inputs A and B.

คำตอบ
(B)
19
A mixture of hydrogen and oxygen has volume 2000 cm³, temperature 300 K, pressure 100 kPa and mass 0.76 g. The ratio of number of moles of hydrogen to number of moles of oxygen in the mixture will be:

[Take gas constant R = 8.3 JK^$$-$$1mol^$$-$$1]
คำตอบ
(B)
$${3 \over 1}$$
20
A 220 V, 50 Hz AC source is connected to a 25 V, 5 W lamp and an additional resistance R in series (as shown in figure) to run the lamp at its peak brightness, then the value of R (in ohm) will be _____________.

คำตอบ
975
21
In Young's double slit experiment the two slits are 0.6 mm distance apart. Interference pattern is observed on a screen at a distance 80 cm from the slits. The first dark fringe is observed on the screen directly opposite to one of the slits. The wavelength of light will be ____________ nm.
คำตอบ
450
22
A beam of monochromatic light is used to excite the electron in Li^{+ +} from the first orbit to the third orbit. The wavelength of monochromatic light is found to be x $$\times$$ 10^$$-$$10 m. The value of x is ___________.

[Given hc = 1242 eV nm]
คำตอบ
114
23
The current density in a cylindrical wire of radius 4 mm is 4 $$\times$$ 10⁶ Am^$$-$$2. The current through the outer portion of the wire between radial distances $${R \over 2}$$ and R is ____________ $$\pi$$ A.
คำตอบ
48
24
A capacitor of capacitance 50 pF is charged by 100 V source. It is then connected to another uncharged identical capacitor. Electrostatic energy loss in the process is ___________ nJ.
คำตอบ
125
25
The area of cross-section of a large tank is 0.5 m². It has a narrow opening near the bottom having area of cross-section 1 cm². A load of 25 kg is applied on the water at the top in the tank. Neglecting the speed of water in the tank, the velocity of the water, coming out of the opening at the time when the height of water level in the tank is 40 cm above the bottom, will be ___________ cms^$$-$$1. [Take g = 10 ms^$$-$$2]
คำตอบ
300
26
A pendulum of length 2 m consists of a wooden bob of mass 50 g. A bullet of mass 75 g is fired towards the stationary bob with a speed v. The bullet emerges out of the bob with a speed $${v \over 3}$$ and the bob just completes the vertical circle. The value of v is ___________ ms^$$-$$1. (if g = 10 m/s²).
คำตอบ
10