JEE MAIN - Physics (2023 - 10th April Evening Shift)

1
A person travels $$x$$ distance with velocity $$v_{1}$$ and then $$x$$ distance with velocity $$v_{2}$$ in the same direction. The average velocity of the person is $$\mathrm{v}$$, then the relation between $$v, v_{1}$$ and $$v_{2}$$ will be.
Answer
(D)
$$\frac{2}{\mathrm{~V}}=\frac{1}{\mathrm{v}_{1}}+\frac{1}{\mathrm{v}_{2}}$$
2

If each diode has a forward bias resistance of $$25 ~\Omega$$ in the below circuit,

JEE Main 2023 (Online) 10th April Evening Shift Physics - Semiconductor Question 38 English

Which of the following options is correct :

Answer
(B)
$$\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}=2$$
3

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A : An electric fan continues to rotate for some time after the current is switched off.

Reason R : Fan continues to rotate due to inertia of motion.

In the light of above statements, choose the most appropriate answer from the options given below.

Answer
(C)
Both A and R are correct and R is the correct explanation of A
4
In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor
Answer
(D)
move in the curved paths from lower potential to higher potential
5
A gas mixture consists of 2 moles of oxygen and 4 moles of neon at temperature T. Neglecting all vibrational modes, the total internal energy of the system will be,
Answer
(D)
11RT
6
A bar magnet is released from rest along the axis of a very long vertical copper tube. After some time the magnet will
Answer
(A)
move down with almost constant speed
7
Two projectiles are projected at $$30^{\circ}$$ and $$60^{\circ}$$ with the horizontal with the same speed. The ratio of the maximum height attained by the two projectiles respectively is:
Answer
(C)
1 : 3
8
A gas is compressed adiabatically, which one of the following statement is NOT true.
Answer
(C)
There is no change in the internal energy
9

For a periodic motion represented by the equation

$$y=\sin \omega \mathrm{t}+\cos \omega \mathrm{t}$$

the amplitude of the motion is

Answer
(B)
$$\sqrt2$$
10
The amplitude of magnetic field in an electromagnetic wave propagating along y-axis is $$6.0 \times 10^{-7} \mathrm{~T}$$. The maximum value of electric field in the electromagnetic wave is
Answer
(C)
$$180 ~\mathrm{Vm}^{-1}$$
11

The time period of a satellite, revolving above earth's surface at a height equal to $$\mathrm{R}$$ will be

(Given $$g=\pi^{2} \mathrm{~m} / \mathrm{s}^{2}, \mathrm{R}=$$ radius of earth)

Answer
(A)
$$\sqrt{32 R}$$
12

Given below are two statements:

Statement I : For diamagnetic substance, $$-1 \leq \chi < 0$$, where $$\chi$$ is the magnetic susceptibility.

Statement II : Diamagnetic substances when placed in an external magnetic field, tend to move from stronger to weaker part of the field.

In the light of the above statements, choose the correct answer from the options given below

Answer
(A)
Both Statement I and Statement II are true
13
The ratio of intensities at two points $$\mathrm{P}$$ and $$\mathrm{Q}$$ on the screen in a Young's double slit experiment where phase difference between two waves of same amplitude are $$\pi / 3$$ and $$\pi / 2$$, respectively are
Answer
(D)
3 : 2
14

Young's moduli of the material of wires A and B are in the ratio of $$1: 4$$, while its area of cross sections are in the ratio of $$1: 3$$. If the same amount of load is applied to both the wires, the amount of elongation produced in the wires $$\mathrm{A}$$ and $$\mathrm{B}$$ will be in the ratio of

[Assume length of wires A and B are same]

Answer
(C)
12 : 1
15

The variation of stopping potential $$\left(\mathrm{V}_{0}\right)$$ as a function of the frequency $$(v)$$ of the incident light for a metal is shown in figure. The work function of the surface is

JEE Main 2023 (Online) 10th April Evening Shift Physics - Dual Nature of Radiation Question 42 English

Answer
(D)
2.07 eV
16

Given below are two statements:

Statement I : Rotation of the earth shows effect on the value of acceleration due to gravity (g)

Statement II : The effect of rotation of the earth on the value of 'g' at the equator is minimum and that at the pole is maximum.

In the light of the above statements, choose the correct answer from the options given below

Answer
(B)
Statement I is true but statement II is false
17
In an experiment with vernier callipers of least count $$0.1 \mathrm{~mm}$$, when two jaws are joined together the zero of vernier scale lies right to the zero of the main scale and 6th division of vernier scale coincides with the main scale division. While measuring the diameter of a spherical bob, the zero of vernier scale lies in between $$3.2 \mathrm{~cm}$$ and $$3.3 \mathrm{~cm}$$ marks, and 4th division of vernier scale coincides with the main scale division. The diameter of bob is measured as
Answer
(A)
$$3 .18 \mathrm{~cm}$$
18
The distance between two plates of a capacitor is $$\mathrm{d}$$ and its capacitance is $$\mathrm{C}_{1}$$, when air is the medium between the plates. If a metal sheet of thickness $$\frac{2 d}{3}$$ and of the same area as plate is introduced between the plates, the capacitance of the capacitor becomes $$\mathrm{C}_{2}$$. The ratio $$\frac{\mathrm{C}_{2}}{\mathrm{C}_{1}}$$ is
Answer
(B)
3 : 1
19
A force of $$-\mathrm{P} \hat{\mathrm{k}}$$ acts on the origin of the coordinate system. The torque about the point $$(2,-3)$$ is $$\mathrm{P}(a \hat{i}+b \hat{j})$$, The ratio of $$\frac{a}{b}$$ is $$\frac{x}{2}$$. The value of $$x$$ is -
Answer
3
20

A straight wire carrying a current of $$14 \mathrm{~A}$$ is bent into a semi-circular arc of radius $$2.2 \mathrm{~cm}$$ as shown in the figure. The magnetic field produced by the current at the centre $$(\mathrm{O})$$ of the arc. is ____________ $$\times ~10^{-4} \mathrm{~T}$$

JEE Main 2023 (Online) 10th April Evening Shift Physics - Magnetic Effect of Current Question 49 English

Answer
2
21

A rectangular block of mass $$5 \mathrm{~kg}$$ attached to a horizontal spiral spring executes simple harmonic motion of amplitude $$1 \mathrm{~m}$$ and time period $$3.14 \mathrm{~s}$$. The maximum force exerted by spring on block is _________ N

Answer
20
22

A square loop of side $$2.0 \mathrm{~cm}$$ is placed inside a long solenoid that has 50 turns per centimetre and carries a sinusoidally varying current of amplitude $$2.5 \mathrm{~A}$$ and angular frequency $$700 ~\mathrm{rad} ~\mathrm{s}^{-1}$$. The central axes of the loop and solenoid coincide. The amplitude of the emf induced in the loop is $$x \times 10^{-4} \mathrm{~V}$$. The value of $$x$$ is __________.

$$ \text { (Take, } \pi=\frac{22}{7} \text { ) } $$

Answer
44
23
If the maximum load carried by an elevator is $$1400 \mathrm{~kg}$$ ( $$600 \mathrm{~kg}$$ - Passengers + 800 $$\mathrm{kg}$$ - elevator), which is moving up with a uniform speed of $$3 \mathrm{~m} \mathrm{~s}^{-1}$$ and the frictional force acting on it is $$2000 \mathrm{~N}$$, then the maximum power used by the motor is __________ $$\mathrm{kW}\left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}\right)$$
Answer
48
24

An electron revolves around an infinite cylindrical wire having uniform linear charge density $$2 \times 10^{-8} \mathrm{C} \mathrm{m}^{-1}$$ in circular path under the influence of attractive electrostatic field as shown in the figure. The velocity of electron with which it is revolving is ___________ $$\times 10^{6} \mathrm{~m} \mathrm{~s}^{-1}$$. Given mass of electron $$=9 \times 10^{-31} \mathrm{~kg}$$

JEE Main 2023 (Online) 10th April Evening Shift Physics - Electrostatics Question 57 English

Answer
8
25
A rectangular parallelopiped is measured as $$1 \mathrm{~cm} \times 1 \mathrm{~cm} \times 100 \mathrm{~cm}$$. If its specific resistance is $$3 \times 10^{-7} ~\Omega \mathrm{m}$$, then the resistance between its two opposite rectangular faces will be ___________ $$\times 10^{-7} ~\Omega$$.
Answer
3
26

Figure below shows a liquid being pushed out of the tube by a piston having area of cross section $$2.0 \mathrm{~cm}^{2}$$. The area of cross section at the outlet is $$10 \mathrm{~mm}^{2}$$. If the piston is pushed at a speed of $$4 \mathrm{~cm} \mathrm{~s}^{-1}$$, the speed of outgoing fluid is __________ $$\mathrm{cm} \mathrm{s}^{-1}$$

JEE Main 2023 (Online) 10th April Evening Shift Physics - Properties of Matter Question 69 English

Answer
80
27

A point object, 'O' is placed in front of two thin symmetrical coaxial convex lenses $$\mathrm{L}_{1}$$ and $$\mathrm{L}_{2}$$ with focal length $$24 \mathrm{~cm}$$ and $$9 \mathrm{~cm}$$ respectively. The distance between two lenses is $$10 \mathrm{~cm}$$ and the object is placed $$6 \mathrm{~cm}$$ away from lens $$\mathrm{L}_{1}$$ as shown in the figure. The distance between the object and the image formed by the system of two lenses is __________ $$\mathrm{cm}$$.

JEE Main 2023 (Online) 10th April Evening Shift Physics - Geometrical Optics Question 52 English

Answer
34
28
If 917 $$\mathop A\limits^o $$ be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be ___________ $$\mathop A\limits^o $$.
Answer
3668