JEE Main 2020 (Online) 5th September Morning Slot

A particle of mass 200 MeV/c2 collides with a
hydrogen atom at rest. Soon after the collision
the particle comes to rest, and the atom
recoils and goes to its first excited state. The
initial kinetic energy of the particle (in eV) is
$${N \...

Activities of three radioactive substances A, B
and C are represented by the curves A, B and
C, in the figure. Then their half-lives
\({T_{{1 \over 2}}}\left( A \right)\) : \({T_{{1 \over 2}}}\left( B \right)\) : $${T_{{1 \over 2}}}\left( C...

Two capacitors of capacitances C and 2C are
charged to potential differences V and 2V,
respectively. These are then connected in
parallel in such a manner that the positive
terminal of one is connected to the negative
terminal of the other....

A galvanometer of resistance G is converted
into a voltmeter of range 0 – 1 V by connecting
a resistance R1 in series with it. The additional
resistance that should be connected in series
with R1 to increase the range of the voltmeter
to 0 ...

An electrical power line, having a total
resistance of 2 \(\Omega\), delivers 1 kW at 220 V. The
efficiency of the transmission line is
approximately :

A beam of electrons of energy E scatters from
a target having atomic spacing of 1 \(\mathop A\limits^o\). The first
maximum intensity occurs at \(\theta\) = 60o. Then E (in
eV) is ______.
(Planck constant h = 6.64 × 10–34 Js, 1 eV =
1.6 ×...

Two concentric circular coils, C1 and C2 are
placed in the XY plane. C1 has 500 turns, and
a radius of 1 cm. C2 has 200 turns and radius
of 20 cm. C2 carries a time dependent current
I(t) = (5t2 – 2t + 3) A where t is in s. The emf
induced ...

An electron is constrained to move along
the y-axis with a speed of 0.1 c (c is the
speed of light) in the presence of
electromagnetic wave, whose electric
field is
$$\overrightarrow E = 30\widehat j\sin \left( {1.5 \times {{10}^7}t - 5 \t...

With increasing biasing voltage of a photodiode,
the photocurrent magnitude :

A solid sphere of radius R carries a charge
Q + q distributed uniformly over its volume. A
very small point like piece of it of mass m gets
detached from the bottom of the sphere and
falls down vertically under gravity. This piece
carries c...

For a concave lens of focal length f, the relation
between object and image distances u and v,
respectively, from its pole can best be
represented by (u = v is the reference line) :

A compound microscope consists of an
objective lens of focal length 1 cm and an
eyepiece of focal length 5 cm with a separation
of 10 cm.
The distance between an object and the
objective lens, at which the strain on the eye is
minimum is $$...

The value of the acceleration due to gravity is
g1 at a height h = \({R \over 2}\) (R = radius of the earth) from the surface of the earth. It is again equal
to g1 at a depth d below the surface of the
earth. The ratio $$\left( {{d \over R}...

Three different processes that can occur in an
ideal monoatomic gas are shown in the P vs V
diagram. The paths are labelled as A \(\to\) B,
A \(\to\) C and A \(\to\) D. The change in internal
energies during these process are taken as...

Number of molecules in a volume of 4 cm3 of
a perfect monoatomic gas at some temperature
T and at a pressure of 2 cm of mercury is close
to? (Given, mean kinetic energy of a molecule
(at T) is 4 \(\times\) 10–14 erg, g = 980 cm/s2, densit...

A bullet of mass 5 g, travelling with a speed of
210 m/s, strikes a fixed wooden target. One half
of its kinetic energy is converted into heat in
the bullet while the other half is converted into
heat in the wood. The rise of temperature of...

A square loop of side 2\(a\), and carrying current
I, is kept in XZ plane with its centre at origin.
A long wire carrying the same current I is
placed parallel to the z-axis and passing
through the point (0, b, 0), (b >> a). The
magnitude o...

A balloon is moving up in air vertically above a
point A on the ground. When it is at a height h1,
a girl standing at a distanced (point B) from A
(see figure) sees it at an angle 45o with respect
to the vertical. When the balloon climbs up...

A helicopter rises from rest on the ground
vertically upwards with a constant acceleration
g. A food packet is dropped from the helicopter
when it is at a height h. The time taken by the
packet to reach the ground is close to :
[g is the
ac...

A hollow spherical shell at outer radius R floats
just submerged under the water surface. The
inner radius of the shell is r. If the specific
gravity of the shell material is \({{27} \over 8}\) w.r.t water,
the value of r is :

A force \(\overrightarrow F = \left( {\widehat i + 2\widehat j + 3\widehat k} \right)\) N acts at a point \(\left( {4\widehat i + 3\widehat j - \widehat k} \right)\) m. Then the magnitude of torque
about the point $$\left( {\widehat i + 2\...

A wheel is rotating freely with an angular speed
\(\omega\) on a shaft. The moment of inertia of the
wheel is I and the moment of inertia of the
shaft is negligible. Another wheel of moment of
inertia 3I initially at rest is suddenly coupl...

A physical quantity z depends on four
observables a, b, c and d, as z = \({{{a^2}{b^{{2 \over 3}}}} \over {\sqrt c {d^3}}}\). The
percentages of error in the measurement of a,
b, c and d are 2%, 1.5%, 4% and 2.5%
respectively. The percentag...

Assume that the displacement(s) of air is
proportional to the pressure difference (\(\Delta\)p)
created by a sound wave. Displacement (s)
further depends on the speed of sound (v),
density of air (\(\rho\)) and the frequency (f). If
$$\De...

In a resonance tube experiment when the tube
is filled with water up to a height of 17.0 cm
from bottom, it resonates with a given tuning
fork. When the water level is raised the next
resonance with the same tuning fork occurs at
a height o...