JEE Main 2020 (Online) 8th January Morning Slot

The graph which depicts the results of
Rutherford gold foil experiment with
\(\alpha\)-particales is :
\(\theta\) : Scattering angle
Y : Number of scattered \(\alpha\)-particles detected
(Plots are schematic and not to scale)

Effective capacitance of parallel combination
of two capacitors C1 and C2 is 10 μF. When
these capacitors are individually connected to
a voltage source of 1V, the energy stored in the
capacitor C2 is 4 times that of C1. If these
capacitors...

A body A, of mass m = 0.1 kg has an initial
velocity of 3\(\widehat i\) ms-1 . It collides elastically with
another body, B of the same mass which has
an initial velocity of 5\(\widehat j\) ms-1. After collision,
A moves with a velocity $$\...

The coordinates of centre of mass of a uniform
flag shaped lamina (thin flat plate) of mass 4kg.
(The coordinates of the same are shown in
figure) are :

A particle of mass m is fixed to one end of a
light spring having force constant k and
unstretched length \(\ell\). The other end is fixed. The
system is given an angular speed \(\omega\) about the
fixed end of the spring such that it rot...

Four resistances of 15\(\Omega\), 12\(\Omega\), 4\(\Omega\) and 10\(\Omega\)
respectively in cyclic order to form
Wheatstone's network. The resistance that
is to be connected in parallel with the
resistance of 10\(\Omega\) to balance t...

The length of a potentiometer wire is 1200 cm
and it carries a current of 60 mA. For a cell of
emf 5V and internal resistance of 20\(\Omega\), the null
point on it is found to be a 1000 cm. The
resistance of whole wire is :

When photon of energy 4.0 eV strikes the
surface of a metal A, the ejected photoelectrons
have maximum kinetic energy TA eV end
de-Broglie wavelength \(\lambda _A\). The maximum
kinetic energy of photoelectrons liberated from
another metal ...

At time t = 0 magnetic field of 1000 Gauss is
passing perpendicularly through the area
defined by the closed loop shown in the figure.
If the magnetic field reduces linearly to
500 Gauss, in the next 5s, then induced EMF
in the loop is :

Boolean relation at the output stage-Y for the
following circuit is :

Three charged particle A, B and C with charges
–4q, 2q and –2q are present on the
circumference of a circle of radius d. the charged
particles A, C and centre O of the circle formed
an equilateral triangle as shown in figure. Electric
field...

In finding the electric field using Gauss Law
the formula \(\left| {\overrightarrow E } \right| = {{{q_{enc}}} \over {{\varepsilon _0}\left| A \right|}}\) is applicable. In the
formula \({{\varepsilon _0}}\) is permittivity of free space, A...

The magnifying power of a telescope with tube
60 cm is 5. What is the focal length of its eye
piece ?

The critical angle of a medium for a specific wavelength, if the medium has relative permittivity 3 and relative permeability \({4 \over 3}\) for this wavelength, will be :

A point object in air is in front of the curved
surface of a plano-convex lens. The radius of
curvature of the curved surface is 30 cm and
the refractive index of the lens material is 1.5,
then the focal length of the lens (in cm)
is ______...

Consider two solid spheres of radii R1 = 1m,
R2 = 2m and masses M1 and M2, respectively.
The gravitational field due to sphere (1) and (2) are shown. The value of \({{{M_1}} \over {{M_2}}}\) is :

The plot that depicts the behavior of the mean
free time t (time between two successive
collisions) for the molecules of an ideal gas, as
a function of temperature (T), qualitatively, is:
(Graphs are schematic and not drawn to scale)

A thermodynamic cycle xyzx is shown on a V-T diagram.

The P-V diagram that best describes this cycle
is : (Diagrams are schematic and not to scale)

Photon with kinetic energy of 1MeV moves
from south to north. It gets an acceleration of
1012 m/s2 by an applied magnetic field (west to
east). The value of magnetic field : (Rest mass
of proton is 1.6 × 10–27 kg) :

A particle is moving along the x-axis with its
coordinate with the time 't' given be x(t) = 10 + 8t – 3t2. Another particle is moving
the y-axis with its coordinate as a function of
time given by y(t) = 5 – 8t3. At t = 1s, the speed
of the ...

Consider a solid sphere of radius R and mass
density \(\rho \left( r \right) = {\rho _0}\left( {1 - {{{r^2}} \over {{R^2}}}} \right)\) , \(0 < r \le R\) The
minimum density of a liquid in which it will
float is :

A leak proof cylinder of length 1m, made of
a metal which has very low coefficient of
expansion is floating vertically in water at 0°C
such that its height above the water surface is
20 cm. When the temperature of water is
increased to 4°C,...

Consider a uniform rod of mass M = 4m and
length \(\ell\) pivoted about its centre. A mass m
moving with velocity v making angle \(\theta = {\pi \over 4}\) to
the rod's long axis collides with one end of the
rod and sticks to it. The ang...

The dimension of stopping potential V0 in photoelectric effect in units of Planck's constant 'h', speed of light 'c' and Gravitational constant 'G' and ampere A is :

A one metre long (both ends open) organ pipe
is kept in a gas that has double the density of
air at STP. Assuming the speed of sound in air
at STP is 300 m/s, the frequency difference
between the fundamental and second harmonic
of this pipe...