JEE MAIN - Physics (2022 - 24th June Morning Shift)

1
The bulk modulus of a liquid is 3 $$\times$$ 10¹⁰ Nm^$$-$$2. The pressure required to reduce the volume of liquid by 2% is :
Respondre
(C)
6 $$\times$$ 10⁸ Nm^$$-$$2
2
Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle.

Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion.
Respondre
(A)
Both (A) and (R) are true and (R) is the correct explanation of (A).
3
Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20 $$\Omega$$. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is :
Respondre
(C)
5 $$\Omega$$
4
Identify the pair of physical quantities which have different dimensions:
Respondre
(D)
Specific heat capacity and Latent heat
5
A projectile is projected with velocity of 25 m/s at an angle $$\theta$$ with the horizontal. After t seconds its inclination with horizontal becomes zero. If R represents horizontal range of the projectile, the value of $$\theta$$ will be :

[use g = 10 m/s²]
Respondre
(D)
$${\cot ^{ - 1}}\left( {{R \over {20{t^2}}}} \right)$$
6
A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms^$$-$$1. The coefficient of friction between the surface and block is 0.5. The distance covered by the block before coming to rest is :

[use g = 9.8 ms^$$-$$2]
Respondre
(B)
9.8 m
7
A boy ties a stone of mass 100 g to the end of a 2 m long string and whirls it around in a horizontal plane. The string can withstand the maximum tension of 80 N. If the maximum speed with which the stone can revolve is $${K \over \pi }$$ rev./min. The value of K is :

(Assume the string is massless and unstretchable)
Respondre
(C)
600
8
A vertical electric field of magnitude 4.9 $$\times$$ 10⁵ N/C just prevents a water droplet of a mass 0.1 g from falling. The value of charge on the droplet will be :

(Given : g = 9.8 m/s²)
Respondre
(B)
2.0 $$\times$$ 10^$$-$$9 C
9
A particle experiences a variable force $$\overrightarrow F = \left( {4x\widehat i + 3{y^2}\widehat j} \right)$$ in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, then Kinetic Energy changes by :
Respondre
(C)
25.0 J
10
The approximate height from the surface of earth at which the weight of the body becomes $${1 \over 3}$$ of its weight on the surface of earth is :

[Radius of earth R = 6400 km and $$\sqrt 3 $$ = 1.732]
Respondre
(B)
4685 km
11
A resistance of 40 $$\Omega$$ is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to the rms value :
Respondre
(A)
2.5 ms
12
The equations of two waves are given by :

y₁ = 5 sin 2$$\pi$$(x - vt) cm

y₂ = 3 sin 2$$\pi$$(x $$-$$ vt + 1.5) cm

These waves are simultaneously passing through a string. The amplitude of the resulting wave is :
Respondre
(A)
2 cm
13
A plane electromagnetic wave travels in a medium of relative permeability 1.61 and relative permittivity 6.44. If magnitude of magnetic intensity is 4.5 $$\times$$ 10^$$-$$2 Am^$$-$$1 at a point, what will be the approximate magnitude of electric field intensity at that point?

(Given : Permeability of free space $$\mu$$₀ = 4$$\pi$$ $$\times$$ 10^$$-$$7 NA^$$-$$2, speed of light in vacuum c = 3 $$\times$$ 10⁸ ms^$$-$$1)
Respondre
(C)
8.48 Vm^$$-$$1
14
Choose the correct option from the following options given below :
Respondre
(C)
A classical atom based on Rutherford's model is doomed to collapse.
15
Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments 'B' and 'C' of mass numbers 105 and 115. The binding energy of nucleons in 'B' and 'C' is 6.4 MeV per nucleon. The energy Q released per fission will be :
Respondre
(D)
176 MeV
16
A parallel plate capacitor is formed by two plates each of area 30$$\pi$$ cm² separated by 1 mm. A material of dielectric strength 3.6 $$\times$$ 10⁷ Vm^$$-$$1 is filled between the plates. If the maximum charge that can be stored on the capacitor without causing any dielectric breakdown is 7 $$\times$$ 10^$$-$$6C, the value of dielectric constant of the material is :

[Use $${1 \over {4\pi {\varepsilon _0}}} = 9 \times {10^9}$$ Nm² C^$$-$$2]
Respondre
(D)
2.33
17
The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point along the axis at a distance $${r \over 2}$$ from the centre is :
Respondre
(C)
$${\left( {{2 \over {\sqrt 5 }}} \right)^3}B$$
18
Two metallic blocks M₁ and M₂ of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M₂ is K then the thermal conductivity of M₁ will be :

[Assume steady state heat conduction]

Respondre
(B)
8 K
19
0.056 kg of Nitrogen is enclosed in a vessel at a temperature of 127$$^\circ$$C. Th amount of heat required to double the speed of its molecules is ____________ k cal.

Take R = 2 cal mole^$$-$$1 K^$$-$$1)
Respondre
12
20
Two identical thin biconvex lens of focal length 15 cm and refractive index 1.5 are in contact with each other. The space between the lenses is filled with a liquid of refractive index 1.25. The focal length of the combination is __________ cm.
Respondre
10
21
As shown in the figure an inductor of inductance 200 mH is connected to an AC source of emf 220 V and frequency 50 Hz. The instantaneous voltage of the source is 0 V when the peak value of current is $${{\sqrt a } \over \pi }$$ A. The value of $$a$$ is ___________.

Respondre
242
22
Sodium light of wavelengths 650 nm and 655 nm is used to study diffraction at a single slit of aperture 0.5 mm. The distance between the slit and the screen is 2.0 m. The separation between the positions of the first maxima of diffraction pattern obtained in the two cases is ___________ $$\times$$ 10^$$-$$5 m.
Respondre
3
23
When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v₁. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v₂. If v₂ = x v₁, the value of x will be __________.
Respondre
2
24
From the top of a tower, a ball is thrown vertically upward which reaches the ground in 6 s. A second ball thrown vertically downward from the same position with the same speed reaches the ground in 1.5 s. A third ball released, from the rest from the same location, will reach the ground in ____________ s.
Respondre
3
25
A ball of mass 100 g is dropped from a height h = 10 cm on a platform fixed at the top of a vertical spring (as shown in figure). The ball stays on the platform and the platform is depressed by a distance $${h \over 2}$$. The spring constant is _____________ Nm^$$-$$1.

(Use g = 10 ms^$$-$$2)

Respondre
120
26
A metre scale is balanced on a knife edge at its centre. When two coins, each of mass 10 g are put one on the top of the other at the 10.0 cm mark the scale is found to be balanced at 40.0 cm mark. The mass of the metre scale is found to be x $$\times$$ 10^$$-$$2 kg. The value of x is ___________.
Respondre
6