JEE Main 2020 (Online) 2nd September Morning Slot

In a reactor, 2 kg of 92U235 fuel is fully used up
in 30 days. The energy released per fission is
200 MeV. Given that the Avogadro number,
N = 6.023 \(\times\) 1026 per kilo mole and 1 eV =
1.6 × 10–19 J. The power output of the reactor i...

A 5 \(\mu\)F capacitor is charged fully by a 220 V
supply. It is then disconnected from the supply
and is connected in series to another
uncharged 2.5 \(\mu\)F capacitor. If the energy
change during the charge redistribution is
$${X \over...

A particle of mass m with an initial velocity \(u\widehat i\)
collides perfectly elastically with a mass 3 m at
rest. It moves with a velocity \(v\widehat j\) after collision,
then, v is given by :

A bead of mass m stays at point P(a, b) on a
wire bent in the shape of a parabola y = 4Cx2
and rotating with angular speed \(\omega\) (see figure).
The value of \(\omega\) is (neglect friction) :

An amplitude modulated wave is represented
by the expression vm = 5(1 + 0.6 cos 6280t)
sin(211 × 104 t) volts
The minimum and maximum amplitudes of the
amplitude modulated wave are, respectively

Consider four conducting materials copper,
tungsten, mercury and aluminium with
resistivity \(\rho\)C, \(\rho\)T, \(\rho\)M and \(\rho\)A respectively. Then :

When radiation of wavelength \(\lambda\) is used to
illuminate a metallic surface, the stopping
potential is V. When the same surface is
illuminated with radiation of wavelength 3\(\lambda\),
the stopping potential is
\({V \over 4}\). If ...

A circular coil of radius 10 cm is placed in a
uniform magnetic field of 3.0 \(\times\) 10–5 T with its
plane perpendicular to the field initially. It is
rotated at constant angular speed about an
axis along the diameter of coil and
perpe...

A plane electromagnetic wave, has frequency
of 2.0 \(\times\) 1010 Hz and its energy density is
1.02 \(\times\) 10–8 J/m3 in vacuum. The amplitude of
the magnetic field of the wave is close
to
( $${1 \over {4\pi {\varepsilon _0}}} = 9 \...

A charged particle (mass m and charge q)
moves along X-axis with velocity V0. When it
passes through the origin it enters a region
having uniform electric field
\(\overrightarrow E = - E\widehat j\) which
extends upto x = d. Equation of ...

A spherical mirror is obtained as shown in the
figure from a hollow glass sphere. If an object
is positioned in front of the mirror, what will be
the nature and magnification of the image of
the object? (Figure drawn as schematic and not
t...

The mass density of a spherical galaxy varies
as
\({K \over r}\) over a large distance ‘r’ from its centre.
In that region, a small star is in a circular orbit
of radius R. Then the period of revolution, T
depends on R as :

A gas mixture consists of 3 moles of oxygen
and 5 moles of argon at temperature T.
Assuming the gases to be ideal and the oxygen
bond to be rigid, the total internal energy (in
units of RT) of the mixture is :

An engine takes in 5 moles of air at 20oC and
1 atm, and compresses it adiabatically to
1/10th of the original volume. Assuming air to
be a diatomic ideal gas made up of rigid
molecules, the change in its internal energy
during this process...

Magnetic materials used for making permanent
magnets (P) and magnets in a transformer (T)
have different properties of the following,
which property best matches for the type of
magnet required?

A beam of protons with speed 4 × 105 ms–1
enters a uniform magnetic field of 0.3 T at an
angle of 60° to the magnetic field. The pitch of
the resulting helical path of protons is close to :
(Mass of the proton = 1.67 \(\times\) 10–27 kg, ...

Train A and train B are running on parallel
tracks in the opposite directions with speeds of
36 km/hour and 72 km/hour, respectively. A
person is walking in train A in the direction
opposite to its motion with a speed of 1.8 km/
hour. Speed...

A cylindrical vessel containing a liquid is
rotated about its axis so that the liquid rises at
its sides as shown in the figure. The radius of
vessel is 5 cm and the angular speed of
rotation is \(\omega\) rad s–1. The difference in the
he...

A uniform cylinder of mass M and radius R is to
be pulled over a step of height a (a < R) by
applying a force F at its centre ‘O’
perpendicular to the plane through the axes of
the cylinder on the edge of the step (see
figure). The minimum ...

Shown in the figure is rigid and uniform one
meter long rod AB held in horizontal position by
two strings tied to its ends and attached to the
ceiling. The rod is of mass ‘m’ and has another
weight of mass 2 m hung at a distance of 75 cm
f...

The least count of the main scale of a vernier
callipers is 1 mm. Its vernier scale is divided
into 10 divisions and coincide with 9 divisions
of the main scale. When jaws are touching
each other, the 7th division of vernier scale
coincides...

If speed V, area A and force F are chosen as
fundamental units, then the dimension of
Young’s modulus will be

Interference fringes are observed on a screen
by illuminating two thin slits 1 mm apart with a
light source (\(\lambda\) = 632.8 nm). The distance
between the screen and the slits is 100 cm. If
a bright fringe is observed on a screen at a
...

Two identical strings X and Z made of same
material have tension TX and TZ in them. If their
fundamental frequencies are 450 Hz and
300 Hz, respectively, then the ratio TX/TZ is

A small block starts slipping down from a point
B on an inclined plane AB, which is making an angle \(\theta\) with the horizontal section BC is
smooth and the remaining section CA is rough
with a coefficient of friction \(\mu\). It is f...