JEE Main 2020 (Online) 3rd September Morning Slot

A 750 Hz, 20 V (rms) source is connected to a
resistance of 100 \(\Omega\), an inductance of 0.1803 H
and a capacitance of 10 \(\mu\)F all in series. The
time in which the resistance (heat capacity
2 J/oC) will get heated by 10oC. (assume...

In a radioactive material, fraction of active
material remaining after time t is 9/16. The
fraction that was remaining after t/2 is

In the circuit shown in the figure, the total charge is 750 \(\mu\)C and the voltage across capacitor C2
is
20 V. Then the charge on capacitor C2
is :

A block of mass m = 1 kg slides with velocity v = 6 m/s on a frictionless horizontal surface and
collides with a uniform vertical rod and sticks to it as shown. The rod is pivoted about O and swings
as a result of the collision making angle...

Model a torch battery of length \(l\) to be made up
of a thin cylindrical bar of radius ‘a’ and a
concentric thin cylindrical shell of radius ‘b’
filled in between with an electrolyte of
resistivity \(\rho\) (see figure). If the battery is...

When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the
maximum kinetic energy of the photoelectrons becomes three times larger. The work function of
the metal is close to :

An elliptical loop having resistance R, of semi major axis a, and semi minor axis b is placed in
magnetic field as shown in the figure. If the loop is rotated about the x-axis with angular frequency
\(\omega\), the average power loss in th...

The magnetic field of a plane electromagnetic wave is
\(\overrightarrow B = 3 \times {10^{ - 8}}\sin \left[ {200\pi \left( {y + ct} \right)} \right]\widehat i\) T
where c = 3 \(\times\) 108
ms–1 is the speed of light.
The corresponding ...

When a diode is forward biased, it has a
voltage drop of 0.5 V. The safe limit of current
through the diode is 10 mA. If a battery of emf
1.5 V is used in the circuit, the value of
minimum resistance to be connected in series
with the diode...

Two isolated conducting spheres S1 and S2 of
radius \({2 \over 3}R\) and \({1 \over 3}R\) have 12 \(\mu\)C and –3 \(\mu\)C
charges, respectively, and are at a large
distance from each other. They are now
connected by a conducting wire. A ...

An observer can see through a small hole on the side of a jar (radius 15 cm) at a point at height of
15 cm from the bottom (see figure). The hole is at a height of 45 cm. When the jar is filled with a
liquid up to a height of 30 cm the same...

A satellite is moving in a low nearly circular orbit around the earth. Its radius is roughly equal to
that of the earth’s radius Re
. By firing rockets attached to it, its speed is instantaneously increased
in the direction of its motion so...

A balloon filled with helium (32oC and 1.7 atm.)
bursts. Immediately afterwards the expansion
of helium can be considered as

Consider a gas of triatomic molecules. The
molecules are assumed to be triangular and
made of massless rigid rods whose vertices
are occupied by atoms. The internal energy of
a mole of the gas at temperature T is :

A bakelite beaker has volume capacity of 500 cc at 30oC. When it is partially filled with Vm
volume
(at 30oC) of mercury, it is found that the unfilled volume of the beaker remains constant as
temperature is varied. If \(\gamma\)(beaker) ...

Magnitude of magnetic field (in SI units) at the
centre of a hexagonal shape coil of side 10 cm,
50 turns and carrying current I (Ampere) in
units of \({{{\mu _0}I} \over \pi }\) is :

A charged particle carrying charge 1 \(\mu\)C is moving with velocity \(\left( {2\widehat i + 3\widehat j + 4\widehat k} \right)\) ms–1. If an external
magnetic field of \(\left( {5\widehat i + 3\widehat j - 6\widehat k} \right)\)× 10–3 T ...

When a long glass capillary tube of radius
0.015 cm is dipped in a liquid, the liquid rises
to a height of 15 cm within it. If the contact angle
between the liquid and glass to close to 0o, the
surface tension of the liquid, in milliNewton ...

Pressure inside two soap bubbles are 1.01 and 1.02 atmosphere, respectively. The ratio of their
volumes is :

Moment of inertia of a cylinder of mass M,
length L and radius R about an axis passing
through its centre and perpendicular to the
axis of the cylinder is I = \(M\left( {{{{R^2}} \over 4} + {{{L^2}} \over {12}}} \right)\). If such a
cylinde...

A person of 80 kg mass is standing on the rim
of a circular platform of mass 200 kg rotating
about its axis at 5 revolutions per minute (rpm).
The person now starts moving towards the
centre of the platform. What will be the
rotational spee...

Using screw gauge of pitch 0.1 cm and
50 divisions on its circular scale, the thickness
of an object is measured. It should correctly be
recorded as

In a Young’s double slit experiment, light of
500 nm is used to produce an interference
pattern. When the distance between the slits
is 0.05 mm, the angular width (in degree) of
the fringes formed on the distance screen is
close to

A uniform thin rope of length 12 m and mass 6 kg hangs vertically from a rigid support and a block
of mass 2 kg is attached to its free end. A transverse short wavetrain of wavelength 6 cm is
produced at the lower end of the rope. What is t...

A cricket ball of mass 0.15 kg is thrown
vertically up by a bowling machine so that it
rises to a maximum height of 20 m after leaving
the machine. If the part pushing the ball applies
a constant force F on the ball and moves
horizontally a...