JEE Main 2020 (Online) 4th September Evening Slot

A series L-R circuit is connected to a battery of emf V. If the circuit is switched on at t = 0, then
the time at which the energy stored in the inductor reaches \(\left( {{1 \over n}} \right)\) times of its maximum value, is :

Find the Binding energy per neucleon for \({}_{50}^{120}Sn\). Mass of proton mp
= 1.00783 U, mass of neutron
mn
= 1.00867 U and mass of tin nucleus mSn = 119.902199 U. (take 1U = 931 MeV)

A capacitor C is fully charged with voltage V0. After disconnecting the voltage source, it is connected
in parallel with another uncharged capacitor of capacitance \({C \over 2}\). The energy loss in the process
after the charge is distribu...

Four resistances 40 \(\Omega\), 60 \(\Omega\), 90 \(\Omega\) and 110 \(\Omega\) make the arms of a quadrilateral ABCD. Across AC is
a battery of emf 40 V and internal resistance negligible.The potential difference across BD in V is
____...

The value of current i1
flowing from A to C in the circuit diagram is :

In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength
obtained is shown in the figure. As the intensity of incident radiation is increased :

The electric field of a plane electromagnetic wave is given by
\(\overrightarrow E = {E_0}\left( {\widehat x + \widehat y} \right)\sin \left( {kz - \omega t} \right)\)
Its magnetic field will be given by :

Identify the operation performed by the circuit given below :

A particle of charge q and mass m is subjected to an electric field E = E0
(1 – \(a\)x2) in the x-direction,
where \(a\) and E0
are constants. Initially the particle was at rest at x = 0. Other than the initial
position the kinetic energy...

The distance between an object and a screen is 100 cm. A lens can produce real image of the
object on the screen for two different positions between the screen and the object. The distance
between these two positions is 40 cm. If the power ...

A body is moving in a low circular orbit about a planet of mass M and radius R. The radius of the
orbit can be taken to be R itself. Then the ratio of the speed of this body in the orbit to the escape
velocity from the planet is:

The change in the magnitude of the volume of an ideal gas when a small additional pressure \(\Delta\)P is
applied at a constant temperature, is the same as the change when the temperature is reduced by
a small quantity \(\Delta\)T at cons...

Match the thermodynamic processes taking place in a system with the correct conditions. In the
table : \(\Delta\)Q is the heat supplied, \(\Delta\)W is the work done and \(\Delta\)U is change in internal energy of the
system.

.tg {bord...

A small ball of mass m is thrown upward with velocity u from the ground. The ball experiences a
resistive force mkv2
where v is its speed. The maximum height attained by the ball is :

A paramagnetic sample shows a net magnetisation of 6 A/m when it is placed in an external
magnetic field of 0.4 T at a temperature of 4 K. When the sample is placed in an external magnetic
field of 0.3 T at a temperature of 24 K, then the m...

A circular coil has moment of inertia 0.8 kg m2
around any diameter and is carrying current to
produce a magnetic moment of 20 Am2
. The coil is kept initially in a vertical position and it can
rotate freely around a horizontal diameter. W...

The speed verses time graph for a particle is shown in the figure. The distance travelled (in m) by
the particle during the time interval t = 0 to t = 5 s will be________.

A cube of metal is subjected to a hydrostatic pressure of 4 GPa. The percentage change in the
length of the side of the cube is close to :
(Given bulk modulus of metal, B = 8 \(\times\) 1010 Pa)

Two identical cylindrical vessels are kept on the ground and each contain the same liquid of density
d. The area of the base of both vessels is S but the height of liquid in one vessel is x1
and in the
other, x2
. When both cylinders are c...

For a uniform rectangular sheet shown in the figure, the ratio of moments of inertia about the axes
perpendicular to the sheet and passing through O (the centre of mass) and O' (corner point) is :

Consider two uniform discs of the same thickness and different radii R1
= R and R2
= \(\alpha\)R made of
the same material. If the ratio of their moments of inertia I1
and I2
, respectively, about their axes
is I1
: I2
= 1 : 16 then t...

A quantity x is given by \(\left( {{{IF{v^2}} \over {W{L^4}}}} \right)\) in terms of moment of inertia I, force F, velocity v, work W and
Length L. The dimensional formula for x is same as that of :

Orange light of wavelength 6000 \(\times\) 10–10 m illuminates a single slit of width 0.6 \(\times\) 10–4 m. The
maximum possible number of diffraction minima produced on both sides of the central maximum is
___________.

The driver of a bus approaching a big wall notices that the frequency of his bus's horn changes
from 420 Hz to 490 Hz when he hears it after it gets reflected from the wall. Find the speed of the
bus if speed of the sound is 330 ms–1.

A person pushes a box on a rough horizontal plateform surface. He applies a force of 200 N over a
distance of 15 m. Thereafter, he gets progressively tired and his applied force reduces linearly with
distance to 100 N. The total distance th...