JEE Main 2021 (Online) 16th March Morning Shift
JEE Main / 30 questions
2026Tue, Mar 16, 2021 3:30 AM30 PYQs
1Alternating Current
An RC circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to :
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2Alternating Current
A sinusoidal voltage of peak value 250 V is applied to a series LCR circuit, in which R = 8\(\Omega\), L = 24 mH and C = 60 \(\mu\)F. The value of power dissipated at resonant condition is 'x' kW. The value of x to the nearest integer is __...
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3Atoms And Nuclei
The first three spectral lines of H-atom in the Balmer series are given \(\lambda\)1, \(\lambda\)2, \(\lambda\)3 considering the Bohr atomic model, the wave lengths of first and third spectral lines $$\left( \frac{\lambda_{1} }{\lambda_{3} ...
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4Capacitor
For changing the capacitance of a given parallel plate capacitor, a dielectric material of dielectric constant K is used, which has the same area as the plates of the capacitor. The thickness of the dielectric slab is \({3 \over 4}\)d, wher...
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5Center Of Mass
Four equal masses, m each are placed at the comers of a square of length (l) as shown in the figure. The moment of inertia of the system about an axis passing through A and parallel to DB would be :
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6Center Of Mass
A ball of mass 10 kg moving with a velocity \(10\sqrt 3\) m s\(-\)1 along X-axis, hits another ball of mass 20 kg which is at rest. After collision, the first ball comes to rest and the second one disintegrates into two equal pieces. One o...
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7Circular Motion
A block of 200 g mass moves with a uniform speed in a horizontal circular groove, with vertical side walls of radius 20 cm. If the block takes 40 s to complete one round, the normal force by the side walls of the groove is :
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8Communication Systems
A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be :
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9Current Electricity
In the figure given, the electric current flowing through the 5 k\(\Omega\) resistor is 'x' mA.The value of x to the nearest integer is ____________.
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10Current Electricity
A conducting wire of length 'l', area of cross-section A and electric resistivity \(\rho\) is connected between the terminals of a battery. A potential difference V is developed between its ends, causing an electric current.If the length of...
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11Dual Nature Of Radiation
The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation :
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12Electromagnetic Induction
A conducting bar of length L is free to slide on two parallel conducting rails as shown in the figure Two resistors R1 and R2 are connected across the ends of the rails. There is a uniform magnetic field \(\overrightarrow B\) pointing into...
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13Electromagnetic Waves
For an electromagnetic wave travelling in free space, the relation between average energy densities due to electric (Ue) and magnetic (Um) fields is :
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14Electromagnetic Waves
A plane electromagnetic wave of frequency 500 MHz is travelling in vacuum along y-direction. At a particular point in space and time, \(\overrightarrow B\) = 8.0 \(\times\) 10\(-\)8 \(\widehat z\)T. The value of electric field at this poin...
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15Electronic Devices
The value of power dissipated across the zener diode (Vz = 15V) connected in the circuit as shown in the figure is x \(\times\) 10\(-\)1 watt.The value of x, to the nearest integer, is __________.
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16Electronic Devices
In the logic circuit shown in the figure, if input A and B are 0 to 1 respectively, the output at Y would be 'x'.The value of x is ____________.
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17Geometrical Optics
The angle of deviation through a prism is minimum when(A) Incident ray and emergent ray are symmetric to the prism.(B) The refracted ray inside the prism becomes parallel to its base(C) Angle of incidence is equal to that of the angle of em...
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18Gravitation
The maximum and minimum distances of a comet from the Sun are 1.6 \(\times\) 1012 m and 8.0 \(\times\) 1010 m respectively. If the speed of the comet at the nearest point is 6 \(\times\) 104 ms\(-\)1, the speed at the farthest point is :
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19Heat And Thermodynamics
In thermodynamics, heat and work are :
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20Heat And Thermodynamics
The volume V of an enclosure contains a mixture of three gases, 16 g of oxygen, 28 g of nitrogen and 44 g of carbon dioxide at absolute temperature T. Consider R as universal gas constant. The pressure of the mixture of gases is :
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21Laws Of Motion
A block of mass m slides along a floor while a force of magnitude F is applied to it at an angle \(\theta\) as shown in figure. The coefficient of kinetic friction is \(\mu\)k. then, the block's acceleration 'a' is given by :(g is accelerat...
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22Magnetic Properties Of Matter
A bar magnet of length 14 cm is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of 18 cm from the center of the magnet. If BH = 0.4 G, the magnetic mo...
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23Motion In A Straight Line
The velocity-displacement graph describing the motion of bicycle is shown in the figure.The acceleration-displacement graph of the bicycle's motion is best described by :
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24Properties Of Matter
The pressure acting on a submarine is 3 \(\times\) 105 Pa at a certain depth. If the depth is doubled, the percentage increase in the pressure acting on the submarine would be : (Assume that atmospheric pressure is 1 \(\times\) 105 Pa densi...
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25Rotational Motion
Consider a 20 kg uniform circular disk of radius 0.2 m. It is pin supported at its center and is at rest initially. The disk is acted upon by a constant force F = 20 N through a massless string wrapped around is periphery as shown in the fi...
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26Rotational Motion
Consider a frame that is made up of two thin massless rods AB and AC as shown in the figure. A vertical force \(\overrightarrow P\) of magnitude 100 N is applied at point A of the frame.Suppose the force is \(\overrightarrow P\) resolved ...
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27Simple Harmonic Motion
Time period of a simple pendulum is T inside a lift when the lift is stationary. If the lift moves upwards with an acceleration g/2, the time period of pendulum will be :
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28Units And Measurements
One main scale division of a vernier callipers is 'a' cm and nth division of the vernier scale coincide with (n \(-\) 1)th division of the main scale. The least count of the callipers in mm is :
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29Units And Measurements
The resistance R = \({V \over I}\), where V = (50 \(\pm\) 2)V and I = (20 \(\pm\) 0.2)A. The percentage error in R is 'x'%. The value of 'x' to the nearest integer is _________.
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30Wave Optics
A fringe width of 6 mm was produced for two slits separated by 1 mm apart. The screen is placed 10 m away. The wavelength of light used is 'x' nm. The value of 'x' to the nearest integer is ____________.
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