JEE Main 2024 (Online) 31st January Morning Shift
JEE Main / 30 questions
2026Wed, Jan 31, 2024 3:30 AM30 PYQs
1Atoms And Nuclei
If the wavelength of the first member of Lyman series of hydrogen is \(\lambda\). The wavelength of the second member will be
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2Atoms And Nuclei
The mass defect in a particular reaction is \(0.4 \mathrm{~g}\). The amount of energy liberated is \(n \times 10^7 \mathrm{~kWh}\), where \(n=\) __________. (speed of light \(\left.=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right)\)
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3Capacitor
A parallel plate capacitor with plate separation \(5 \mathrm{~mm}\) is charged up by a battery. It is found that on introducing a dielectric sheet of thickness \(2 \mathrm{~mm}\), while keeping the battery connections intact, the capacitor ...
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4Center Of Mass
An artillery piece of mass \(M_1\) fires a shell of mass \(M_2\) horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is:
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5Center Of Mass
A solid circular disc of mass \(50 \mathrm{~kg}\) rolls along a horizontal floor so that its center of mass has a speed of \(0.4 \mathrm{~m} / \mathrm{s}\). The absolute value of work done on the disc to stop it is ________ J.
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6Center Of Mass
A body starts falling freely from height \(H\) hits an inclined plane in its path at height \(h\). As a result of this perfectly elastic impact, the direction of the velocity of the body becomes horizontal. The value of \(\frac{H}{h}\) for ...
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7Circular Motion
A coin is placed on a disc. The coefficient of friction between the coin and the disc is \(\mu\). If the distance of the coin from the center of the disc is \(r\), the maximum angular velocity which can be given to the disc, so that the coi...
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8Current Electricity
Two conductors have the same resistances at \(0^{\circ} \mathrm{C}\) but their temperature coefficients of resistance are \(\alpha_1\) and \(\alpha_2\). The respective temperature coefficients for their series and parallel combinations are ...
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9Current Electricity
Equivalent resistance of the following network is __________ \(\Omega\).
INTEGER+4 / -12024
10Dual Nature Of Radiation
When a metal surface is illuminated by light of wavelength \(\lambda\), the stopping potential is \(8 \mathrm{~V}\). When the same surface is illuminated by light of wavelength \(3 \lambda\), stopping potential is \(2 \mathrm{~V}\). The thr...
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11Electromagnetic Induction
A coil is places perpendicular to a magnetic field of \(5000 \mathrm{~T}\). When the field is changed to \(3000 \mathrm{~T}\) in \(2 \mathrm{~s}\), an induced emf of \(22 \mathrm{~V}\) is produced in the coil. If the diameter of the coil is...
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12Electromagnetic Induction
A small square loop of wire of side \(l\) is placed inside a large square loop of wire of side \(L\left(L=l^2\right)\). The loops are coplanar and their centers coincide. The value of the mutual inductance of the system is $$\sqrt{x} \times...
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13Electromagnetic Waves
In a plane EM wave, the electric field oscillates sinusoidally at a frequency of \(5 \times 10^{10} \mathrm{~Hz}\) and an amplitude of \(50 \mathrm{~Vm}^{-1}\). The total average energy density of the electromagnetic field of the wave is : ...
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14Electronic Devices
Identify the logic operation performed by the given circuit.
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15Electrostatics
Two charges \(q\) and \(3 q\) are separated by a distance '\(r\)' in air. At a distance \(x\) from charge \(q\), the resultant electric field is zero. The value of \(x\) is :
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16Geometrical Optics
The refractive index of a prism with apex angle \(A\) is \(\cot A / 2\). The angle of minimum deviation is :
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17Gravitation
Four identical particles of mass \(m\) are kept at the four corners of a square. If the gravitational force exerted on one of the masses by the other masses is \(\left(\frac{2 \sqrt{2}+1}{32}\right) \frac{\mathrm{Gm}^2}{L^2}\), the length o...
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18Heat And Thermodynamics
The given figure represents two isobaric processes for the same mass of an ideal gas, then
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19Heat And Thermodynamics
The parameter that remains the same for molecules of all gases at a given temperature is :
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20Laws Of Motion
In the given arrangement of a doubly inclined plane two blocks of masses \(M\) and \(m\) are placed. The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of friction between the surface of the pl...
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21Magnetics
A rigid wire consists of a semicircular portion of radius \(R\) and two straight sections. The wire is partially immerged in a perpendicular magnetic field \(B=B_0 \hat{k}\) as shown in figure. The magnetic force on the wire if it has a cur...
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22Magnetics
An electron moves through a uniform magnetic field \(\vec{B}=B_0 \hat{i}+2 B_0 \hat{j} T\). At a particular instant of time, the velocity of electron is \(\vec{u}=3 \hat{i}+5 \hat{j} \mathrm{~m} / \mathrm{s}\). If the magnetic force acting ...
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23Motion In A Straight Line
The relation between time '\(t\)' and distance '\(x\)' is \(t=\alpha x^2+\beta x\), where \(\alpha\) and \(\beta\) are constants. The relation between acceleration \((a)\) and velocity \((v)\) is :
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24Properties Of Matter
A small steel ball is dropped into a long cylinder containing glycerine. Which one of the following is the correct representation of the velocity time graph for the transit of the ball?
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25Properties Of Matter
The depth below the surface of sea to which a rubber ball be taken so as to decrease its volume by \(0.02 \%\) is _______ \(m\).
(Take density of sea water \(=10^3 \mathrm{kgm}^{-3}\), Bulk modulus of rubber $$=9 \times 10^8 \mathrm{~Nm}^{-...
(Take density of sea water \(=10^3 \mathrm{kgm}^{-3}\), Bulk modulus of rubber $$=9 \times 10^8 \mathrm{~Nm}^{-...
INTEGER+4 / -12024
26Simple Harmonic Motion
A particle performs simple harmonic motion with amplitude \(A\). Its speed is increased to three times at an instant when its displacement is \(\frac{2 A}{3}\). The new amplitude of motion is \(\frac{n A}{3}\). The value of \(n\) is _______...
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27Units And Measurements
If the percentage errors in measuring the length and the diameter of a wire are \(0.1 \%\) each. The percentage error in measuring its resistance will be:
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28Units And Measurements
A force is represented by \(F=a x^2+b t^{\frac{1}{2}}\)
where \(x=\) distance and \(t=\) time. The dimensions of \(b^2 / a\) are:
where \(x=\) distance and \(t=\) time. The dimensions of \(b^2 / a\) are:
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29Wave Optics
Two waves of intensity ratio \(1: 9\) cross each other at a point. The resultant intensities at that point, when (a) Waves are incoherent is \(I_1\) (b) Waves are coherent is \(I_2\) and differ in phase by \(60^{\circ}\). If $$\frac{I_1}{I_...
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30Waves
The fundamental frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe. If length of the open pipe is \(60 \mathrm{~cm}\), the length of the closed pipe will be:
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