AIIMS 2019

Which of the following can react with \(\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7\) ?

Out of \(\mathrm{BeF}_2, \mathrm{MgF}_2, \mathrm{CaF}_2, \mathrm{SrF}_2\) which has maximum solubility?

The tetrahedral voids are present in 0.5 mole of hcp crystal structure

Which of the following is correct order of
packing efficiency?

Assertion : ZnO becomes yellow when it is
heated.
Reason : The anionic sites occupied by
unpaired electrons (due to F-centres).

The vapour pressure of pure \(\mathrm{CHCl}_3\) and \(\mathrm{CH}_2 \mathrm{Cl}_2\) are 200 and \(41.5 \mathrm{~atm}\) respectively. The weight of \(\mathrm{CHCl}_3\) and \(\mathrm{CH}_2 \mathrm{Cl}_2\) are respectively \(11.9 \mathrm{~g}\)...

If boiling point of water is \(100^{\circ} \mathrm{C}\). How much gram of \(\mathrm{NaCl}\) is added in \(500 \mathrm{~g}\) of water to increase its boiling point of water by approx $$1^{\circ} \mathrm{C}\left(K_b\right)_{\mathrm{H}_2 \math...

Find empirical formula of the compound if \(M=68 \%\) (atomic mass \(=34\) ) and remaining \(32 \%\) oxygen.

Order of acidic nature

Compare stability of free radicals
(I) \(\mathrm{CH}_3-\mathop C\limits^ \bullet H-\mathrm{CH}_3\)
(II)
(III) \(\mathop C\limits^ \bullet {H_2}-\mathrm{CH}\left(\mathrm{CH}_3\right)_2\)
(IV) $$\mathop C\limits^ \bullet {H_2}-\mathrm{CH}...

(i) \(\mathrm{F}_3 \mathrm{C}-\mathrm{COOH}\), (ii) \(\mathrm{CH}_3 \mathrm{COOH}\),
(iii) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH}\), (iv) \(\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{COOH}\)
Correct order of \(\mathrm{p} K_a\) value is

Write IUPAC name of following compound.

Correct order of basic strength is

Which is most stable conformer of ethan-1,
2-diol?

A bulb is emitted electromagnetic radiation of \(660 \mathrm{~nm}\) wavelength. The total energy of radiation is \(3 \times 10^{-18} \mathrm{~J}\). The number of emitted photon will be
$$\left(h=6.6 \times 10^{-34}\right) \mathrm{J} \times ...

Assertion : The chemical properties of
different isotope are same.
Reason : Isotopes having same number of
neutron.

Assertion : A spherical water drops become
flaton flatter surface.
Reason : It become flat due to gravity.

The correct relation is

At \(25^{\circ} \mathrm{C}, 1\) mole of butane is heated then \(\mathrm{CO}_2\) and \(\mathrm{H}_2 \mathrm{O}\) liquid is formed work done is

Assertion : \(U\) is state function.
Reason : \(T\) is an intensive property.

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.