AIIMS 2019

A transformer with turns ratio \(\frac{N_1}{N_2}=\frac{50}{1}\) is connected to a \(120 \mathrm{~V}\) AC supply. If primary and secondary circuit resistances are \(1.5 \mathrm{~k} \Omega\) and \(1 \Omega\) respectively, then find out power ...

If maximum energy is stored in a capacitor
at t = 0, then find the time after which
current in the circuit will be maximum.

In a \(L C R\) series circuit source voltage is \(120 \mathrm{~V}\) and voltage in inductor \(50 \mathrm{~V}\) and resistance is \(40 \mathrm{~V}\), then determine voltage in the capacitor

15 eV is given to electron in 4th orbit then
find its final energy when it comes out of
H-atom.

If half life of an element is \(69.3 \mathrm{~h}\), then how much of its percent will decay in 10th to 11th \(\mathrm{h}\). Initial activity \(=50 ~\mu \mathrm{~Ci}\)

Assertion : Heavy water is used to slow
neutron in nuclear reactor.
Reason : It does not react with slow neutron
and mass of deuterium is comparable to the
neutron.

Assertion : For an element generally \(N \geq Z\) ( \(N=\) number of neutrons, \(Z=\) atomic number)
Reason : Neutrons always experience attractive nuclear force.

In the given circuit, find charge on capacitor after 1s of opening the switch at \(t=\infty\).

A capacitor of capacitance \(15 \mu \mathrm{F}\) having dielectric slab of \(\varepsilon_r=2.5\), dielectric strength \(30 \mathrm{~MV} / \mathrm{m}\) and potential difference \(=30 \mathrm{~V}\). Calculate the area of the plate.

A body of mass \(5 \times 10^3 \mathrm{~kg}\) moving with speed \(2 \mathrm{~m} / \mathrm{s}\) collides with a body of mass \(15 \times 10^3 \mathrm{~kg}\) inelastically and sticks to it. Then loss in \(\mathrm{KE}\) of the system will be

Assertion : There is no loss in energy in elastic collision.
Reason : Linear momentum is conserved in elastic collision.

Assertion : Even though net external force
on a body is zero, momentum need not to
conserved.
Reason : The internal interaction between
particles of a body cancels out momentum of
each other.

An electron is moving in a circle of radius
2m with speed of 4 m/s. Find the
acceleration of the electron.

If modulation index, \(\mu=\frac{1}{2}\) and \(V_m=2\), then \(V_C\) is

Assertion : In ionospheric reflection, phase
change does not occur with the radio wave.
Reason : The ionosphere reflection is similar
to the total internal reflection in miraj.

Assertion : Amplitude modulation shows
more interference than frequency
modulation with noise.
Reason : Interference is function of amplitude
of modulation wave with carrier-wave.

For a wire \(\frac{R}{\ell}=\frac{1}{2}\) and length of wire is \(\ell=5 \mathrm{~cm}\). If potential difference of \(\mathrm{l} \mathrm{V}\) is applied across it, then current through wire will be (\(R=\) Resistance)

A current of \(10 \mathrm{~A}\) is passing through a metallic wire of cross-sectional area \(4 \times 10^{-6} \mathrm{~m}^2\). If the density of the aluminium conductor is \(2.7 \mathrm{~gm} / \mathrm{cc}\) considering aluminium gives 1 ele...

If temperature of Sun \(=6000 \mathrm{~K}\), radius of Sun is \(7.2 \times 10^5 \mathrm{~km}\), radius of Earth \(=6000 \mathrm{~km}\) and distance between Earth and Sun \(=15 \times 10^7 \mathrm{~km}\). Find intensity of light on Earth.

Assertion : In both radioactivity and
photoelectric effect electrons may be ejected.
Reason : In photoelectric effect and
radioactivity emission occurs only of
unstable elements.

Assertion : A metallic surface is moved in
and out in magnetic field then emf is
induced in it.
Reason : Eddy current will be produced in a
metallic surface moving in and out of
magnetic field.

If focal length of objective and eye lenses are \(10 \mathrm{~cm}\) and \(10 \mathrm{~mm}\) respectively and tube length is \(11 \mathrm{~cm}\) then angular magnification of telescope is

Calculate the focal length of given lens if the
magnification is \(-\)0 5.

Find gravitational field at a distance of \(2000 \mathrm{~km}\) from the centre of earth. (Given
\(R_{\text {earth }}=6400 \mathrm{~km}, r=2000 \mathrm{~km} \text {, } M_{\text {earth }}=6 \times 10^{24} \mathrm{~kg} \text { ) }\)

The temperature of food material in
refrigerator is 4\(^\circ\)C and temperature of
environment is 15\(^\circ\)C. If carnot cycle is used
in its working gas, then find its carnot
efficiency.

If \(7 \mathrm{~gm} \mathrm{~N}_2\) is mixed with \(20 \mathrm{~gm} \mathrm{~Ar}\), there \(\frac{C_p}{C_V}\) of mixture will be

In an isobaric process, the work done by a
di-atomic gas is 10 J, the heat given to the
gas will be

Calculate radiation power for sphere whose temperature is 227\(^\circ\)C, radius 2 m and emissivity 0.8.

An ideal gas initially at pressure 1 bar is being compressed from \(30 \mathrm{~m}^3\) to \(10 \mathrm{~m}^3\) volume and its temperature decreases from \(320 \mathrm{~K}\) to \(280 \mathrm{~K}\), then find final pressure of the gas.

Assertion : Vibrational degree of freedom of
a di-atomic gas molecule appears at every
high temperature.
Reason : Di-atomic gas has two vibrational
degree of freedom in one direction.

Assertion : \(\mathrm{NH}_3\) is liquidities more easily than \(\mathrm{CO}_2\).
Reason : Critical temperature of \(\mathrm{NH}_3\) is more than \(\mathrm{CO}_2\).

Assertion : In adiabatic process work is
independent of the path.
Reason : In adiabatic process work done is
equal to negative of change in internal
energy.

A gun applied a force $F$ on a bullet which is given by \(F=\left(100-0.5 \times 10^5 t\right) \mathrm{N}\). The bullet emerges out with speed \(400 \mathrm{~m} / \mathrm{s}\). Then find out the impulse exerted till force on the bullet beco...

Assertion : A glass ball is dropped on
concrete floor can easily get broken
compared if it is dropped on wooden floor.
Reason : On concrete floor glass ball will take
less time to come to rest.

\(\alpha\)-particle is revolving in a circular path with radius \(r\) with speed \(v\), then find the value of magnetic dipole moment.

Assertion : Paramagnetic substances get
poorly attracted in magnetic field.
Reason : Because magnetic dipoles are
aligned along external magnetic field weakly.

A proton is projected with velocity \(\mathbf{v}=2 \hat{\mathbf{i}}\) in a region where magnetic field \(\mathbf{B}=(\hat{\mathbf{i}}+3 \hat{\mathbf{j}}+4 \hat{\mathbf{k}}) \mu \mathrm{T}\) and electric field $$\mathbf{E}=10 \hat{\mathbf{i}...

In figure, two parallel infinitely long current carrying wires are shown. If resultant magnetic field at point \(A\) is zero. Then determine the value of current \(I\).

Two circular loops having same radius \((R=10 \mathrm{~cm})\) and same current \(\frac{7}{2} \mathrm{~A}\) are placed along same axis as shown. If distance between their centres is \(10 \mathrm{~cm}\), find net magnetic field at point \(P\)...

If two protons are moving with speed \(v=4.5 \times 10^5 \mathrm{~m} / \mathrm{s}\) parallel to each other then find the ratio of electrostatic and magnetic force between them

Assertion : Electron moving perpendicular
to B will perform circular motion.
Reason : Force by magnetic field is
perpendicular to velocity.

Assertion : A charge particle is released
from rest in magnetic field then it will move
in a circular path.
Reason : Work done by magnetic field is non
zero.

If a small orifice is made at a height of
0.25 m from the ground, the horizontal
range of water stream will be

Determine the pressure difference in tube of
non-uniform cross sectional area as shown
in figure.
\(\Delta P=?, d_1=5 \mathrm{~cm}, v_1=4 \mathrm{~m} / \mathrm{s}, d_2=2 \mathrm{~cm}, v_2=?\)

In an isothermal process 2 water drops of radius \(1 \mathrm{~mm}\) are combined to form a bigger drop. Find the energy change in this process if \(T=0.1 \mathrm{~N} / \mathrm{m}\).

Assertion : Water drops take spherical shape
when falling freely.
Reason : Water has minimum surface
tension among all liquids.

Assertion : Sometimes insects can walk on
water.
Reason : The gravitational force on insect is
balanced by force due surface tension.

A sphere pure rolls on a rough inclined
plane with initial velocity 2.8 m/s. Find the
maximum distance on the inclined plane.

The given transistor operates in saturation region then what should be the value of \(V_{B B}\) ?
$$\begin{aligned}
& \left(R_{\text {out }}=200 \Omega, R_{\text {in }}=100 \mathrm{~k} \Omega, V_{C C}=3 \mathrm{~V},\right. \\\\
& \left.V_{B...

If voltage across a zener diode is 6V, then
find out the value of maximum resistance in
this condition.