COMEDK 2020
Paper was held on
Wed, Aug 19, 2020 8:30 AM
Chemistry
The number of gram molecules of chlorine in $$6.02\times10^{25}$$ hydrogen chloride molecules is
View Question Which one of the following has maximum
number of atoms of oxygen?
View Question Which one of the following shows functional
isomerism?
View Question In the ionic equation,
$$\mathrm{BiO_3^-+6H^++xe^-\rightarrow Bi^{3+}+3H_2O}$$,
the value of x is
View Question Molarity of a given orthophosphoric acid
solution is 3M. It’s normality is
View Question Acidified sodium fusion extract on addition of
ferric chloride solution gives blood red
colouration which confirms the p
View Question A body of mass 10 mg is moving with a velocity of 100 ms$$^{-1}$$. The wavelength of de-Broglie wave associated with it
View Question Mg$$^{2+}$$ is isoelectronic with
View Question Presence of halogen in organic compounds can be detected using
View Question The electronic configuration of Cr$$^{3+}$$ is
View Question The mass of a metal, with equivalent mass 31.75, which would combine with 8 g of oxygen is
View Question Benzene reacts with chlorine in sunlight to give a final product
View Question In the periodic table metals usually used as catalysts belong to
View Question The general formula of a cycloalkene is
View Question In acetylene molecule, between the carbon atoms there are
View Question Denatured alcohol is
View Question During the formation of a chemical bond
View Question +I-effect is shown by
View Question Formation of coloured solution is possible,
when metal ion in the compound contains
View Question Which of the following is an intensive property?
View Question Hofmann’s bromamide reaction is to convert
View Question IUPAC name of Na$$_3$$[Co(NO$$_2$$)$$_6$$] is
View Question Thermodynamic standard conditions of
temperature and pressure are
View Question How many chiral carbon atoms are present in
2, 3, 4-trichloropentane ?
View Question The number of unidentate ligands in the
complex ion is called
View Question $$2S{O_2}(g) + {O_2}(g)\buildrel {{V_2}{O_5}} \over
\rightleftharpoons $$ is an example for
View Question The amino acid which is not optically active is
View Question For a stable molecule the value of bond order
must be
View Question Which one of the following is a second order
reaction?
View Question According to Baeyer's strain theory which is highly stable?
View Question The number of antibonding electron pairs in O$$_2^{2-}$$ molecular ion on the basis of molecular orbital theory is
[Atom
View Question Hydroxyl ion concentration of 1M HCl is
View Question Geometrical isomerism is shown by
View Question The oxidation state of iron in K$$_4$$[Fe(CN)$$_6$$] is,
View Question In which of the following process, a maximum
increase in entropy is observed?
View Question Decomposition of benzene diazonium chloride by using Cu$$_2$$Cl$$_2$$/HCl to form chlorobenzene is
View Question Which complex cannot ionise in solution?
View Question Consider the reaction,
C(s) + O$$_2$$(g) $$\rightarrow$$ CO$$_2$$(g) + 393.5 kJ
The signs of $$\Delta H,\Delta S$$ and $
View Question The product formed when hydroxylamine
condenses with a carbonyl compound is called
View Question Which of the following forms a colourless
solution in aqueous medium?
View Question An alkyl halide reacts with alcoholic ammonia in
a sealed tube, the product formed will be
View Question Entropy of the universe is
View Question Which of the following salts on being dissolved in water gives pH > 7 at 25$$^\circ$$C ?
View Question The reagent used in Clemmenson's reduction is
View Question When KBr is dissolved in water, K$$^+$$ ions are
View Question The volume of 10N and 4N HCl required to
make 1 litre of 7N HCl are
View Question Carbon forms two oxides which have different
compositions. The equivalent mass of which
remains constant?
View Question Maximum number of molecules of CH$$_3$$I that can react with a molecule of CH$$_3$$NH$$_2$$ are
View Question Mathematics
$${7^{2{{\log }_7}5}}$$ is equal to
View Question In the group $$(G\,{ \otimes _{15}})$$, where $$G = \{ 3,6,9,12\} $$, $${ \otimes _{15}}$$ is multiplication modulo 15,
View Question A group (G *) has 10 elements. The minimum number of elements of G, which are their own inverses is
View Question If a and b are vectors such that $$|a + b|=|a-b|$$, then the angle between a and b is
View Question $${{3{x^2} + 1} \over {{x^2} - 6x + 8}}$$ is equal to
View Question If $$a = 2\widehat i + 3\widehat j - \widehat k,b = \widehat i + 2\widehat j - 5\widehat k,c = 3\widehat i + 5\widehat j
View Question OA and BO are two vectors of magnitudes 5 and 6 respectively. If $$\angle BOA=60^\circ$$, then OA . OB is equal to
View Question A vector perpendicular to the plane containing the points $$A(1, - 1,2),B(2,0, - 1),C(0,2,1)$$ is
View Question $${1 \over {2\,.\,5}} + {1 \over {5\,.\,8}} + {1 \over {8\,.\,11}} + .............
+ {1 \over {(3n - 1)(3n + 2)}} = $$
View Question The ninth term of the expansion $${\left( {3x - {1 \over {2x}}} \right)^8}$$ is
View Question If $$A = \left[ {\matrix{
1 & { - 1} & 1 \cr
2 & 1 & { - 3} \cr
1 & 1 & 1 \cr
} } \right],10B = \left[
View Question If $$A = \left[ {\matrix{
0 & x & {16} \cr
x & 5 & 7 \cr
0 & 9 & x \cr
} } \right]$$ is singular, then
View Question If $$A = \left[ {\matrix{
1 & { - 2} & 2 \cr
0 & 2 & { - 3} \cr
3 & { - 2} & 4 \cr
} } \right]$$, then
View Question If $$f:R \to R$$ is defined by $$f(x) = |x|$$, then
View Question The value of $$\left| {\matrix{
x & p & q \cr
p & x & q \cr
p & q & x \cr
} } \right|$$ is
View Question The number of common tangents to the circles $$x^2+y^2=4$$ and $$x^2+y^2-6x-8y-24=0$$ is,
View Question If $$3x+y+k=0$$ is a tangent to the circle $$x^2+y^2=10$$, the values of k are
View Question The equation to two circles which touch the
Y-axis at (0, 3) and make an intercept of 8 units
on X-axis are
View Question The orthocentre of the triangle with vertices A(0, 0), B(0, 3/2), C($$-$$5, 0) is
View Question $${x^2} + {y^2} - 6x - 6y + 4 = 0$$, $${x^2} + {y^2} - 2x - 4y + 3 = 0$$, $${x^2} + {y^2} + 2kx + 2y + 1 = 0$$. If the r
View Question If the circles $${x^2} + {y^2} - 2x - 2y - 7 = 0$$ and $${x^2} + {y^2} + 4x + 2y + k = 0$$ cut orthogonally, then the le
View Question The coordinates of the foot of the perpendicular drawn from the point (3, 4) on the line $$2x+y-7=0$$ is
View Question The area enclosed by the pair of lines $$xy=0$$, the line $$x-4=0$$ and $$y+5=0$$ is
View Question If the area of the auxillary circle of the ellipse $${{{x^2}} \over {{a^2}}} + {{{y^2}} \over {{b^2}}} = 1(a > b)$$ is t
View Question A graph G has m vertices of odd degree and ‘n’
vertices of even degree. Then which of the
following statements is necess
View Question If p is any point on the ellipse $${{{x^2}} \over {36}} + {{{y^2}} \over {16}} = 1$$, and S and S' are the foci, then $$
View Question The value of $$\sin \left[ {2{{\cos }^{ - 1}}{{\sqrt 5 } \over 3}} \right]$$ is
View Question If $${{{x^2}} \over {36}} - {{{y^2}} \over {{k^2}}} = 1$$ is a hyperbola, then which of the following statements can be
View Question The focus of the parabola is
View Question The solution of $${\tan ^{ - 1}}x + 2{\cot ^{ - 1}}x = {{2\pi } \over 3}$$ is
View Question $${\sin ^2}17.5^\circ + \sin 72.5^\circ $$ is equal to
View Question The conjugate of the complex number $${{{{(1 + i)}^2}} \over {1 - i}}$$ is
View Question ABC is a triangle with $$\angle A=30^\circ$$ and BC = 10 cm. The area of the circumcircle of the triangle is
View Question If $$\sin 3\theta = \sin \theta $$, how many solutions exist such that $$ - 2\pi
View Question The imaginary part of $$i^i$$ is
View Question The amplitude of $${(1 + i)^5}$$ is
View Question ABC is a triangle, G is the centroid, D is the mid-point of BC. If A = (2, 3) and G = (7, 5), then the point D is
View Question $$\mathop {\lim }\limits_{x \to 1} {{\tan ({x^2} - 1)} \over {x - 1}}$$ is equal to
View Question If $$y = {2^{\log x}}$$, then $${{dy} \over {dx}}$$ is
View Question If $${\sec ^{ - 1}}\left( {{{1 + x} \over {1 - y}}} \right) = a$$, then $${{dy} \over {dx}}$$ is
View Question If $$y = {\cos ^2}{{3x} \over 2} - {\sin ^2}{{3x} \over 2}$$, then $${{{d^2}y} \over {d{x^2}}}$$ is
View Question If the function $$f(x) = \left\{ {\matrix{
{{{1 - \cos x} \over {{x^2}}},} & {\mathrm{for}\,x \ne 0} \cr
{k,} &
View Question If $$1,\omega ,{\omega ^2}$$ are the cube roots of unity, then $$(1 + \omega )(1 + {\omega ^2})(1 + {\omega ^4})(1 + {\o
View Question If $${x^x} = {y^y}$$, then $${{dy} \over {dx}}$$ is
View Question The point on the curve $$y^2=x$$, the tangent at which makes an angle 45$$^\circ$$ with X-axis is
View Question The length of the subtangent to the curve $${x^2}{y^2} = {a^4}$$ at $$( - a,a)$$ is
View Question The number of positive divisors of 252 is
View Question The remainder obtained when 5124 is divided by 124 is
View Question Which of the following is not a group with
respect to the given operation?
View Question The range in which $$y = - {x^2} + 6x - 3$$ is increasing, is
View Question The value of the integral $$\int\limits_0^{\pi /2} {({{\sin }^{100}}x - {{\cos }^{100}}x)dx} $$ is
View Question OA and OB are two roads enclosing an angle of
120$$^\circ$$. X and Y start from O at the same time. X
travels along OA w
View Question If $$k\int\limits_0^1 {x\,.\,f(3x)dx = \int\limits_0^3 {t\,.\,f(t)dt} } $$, then the value of $$k$$ is
View Question The value of $$\int {{1 \over {1 + \cos 8x}}dx} $$ is
View Question The value of $$\int {{e^x}({x^5} + 5{x^4} + 1)\,.\,dx} $$ is
View Question The value of $$\int {{{{x^2} + 1} \over {{x^2} - 1}}dx} $$ is
View Question The area bounded by the curve $$x=4-y^2$$ and the Y-axis is
View Question The differential equation of the family of
straight lines whose slope is equal to y-intercept
is
View Question The order and degree of the differential equation $${\left[ {1 + {{\left( {{{dy} \over {dx}}} \right)}^5}} \right]^{{1 \
View Question Physics
Light of frequency 1015 Hz falls on a metal surface of work function 2.5 eV. The stopping potential of photoelectrons (i
View Question A proton accelerated through a potential V has de-Broglie wavelength $$\lambda$$. Then, the de-Broglie wavelength of an
View Question Consider a thin spherical shell of radius R
consisting of uniform surface charge density s.
The electric field at a poin
View Question An electron of an atom transits from $$n_1$$ to $$n_2$$. In which of the following maximum frequency of photon will be e
View Question Two protons are kept at a separation of 40 $$\mathop A\limits^o $$. F$$_n$$ is the nuclear force and F$$_e$$ is the elec
View Question Two radioactive materials X$$_1$$ and X$$_2$$ have decay constant 5$$\lambda$$ and $$\lambda$$, respectively. If initial
View Question The Poisson's ratio of a material is 0.1. If the longitudinal strain of a rod of this material is $$10^{-3}$$, then the
View Question A satellite can be in a geostationary orbit around a planet if it is at a distance R from the centre of the planet. If t
View Question When a $$p$$-$$n$$ junction diode is connected in forward bias, its barrier potential
View Question A ball floats on the surface of water in a
container exposed to the atmosphere. When the
container is covered and the ai
View Question A frame made of metallic wire enclosing a surface area A is covered with a soap film. If the area of the frame of metall
View Question A compound slab is made of two parallel plates
of copper and brass of the same thickness and
having thermal conductiviti
View Question In mm$$^3$$ of a gas is compressed at 1 atmospheric pressure and temperature 27$$^\circ$$C to 627$$^\circ$$C. What is th
View Question If sink is at a temperature of $$-39\Upsilon$$C and source at 0$$^\circ$$C, then efficiency will be
View Question Which of the following laws of Physics is valid
across all domains of nature?
View Question A particle of mass m is moving in a horizontal
circle of radius R under a centripetal force equal
to $$-\frac{A}{R^2}$$
View Question A force of 20 N is applied on a body of mass
5 kg resting on a horizontal plane. The body
gains a kinetic energy of 10 J
View Question A body under the action of a force $$F = 6\widehat i - 8\widehat j + 10\widehat k$$, acquires an acceleration of 1 m/s2.
View Question A body of mass 1000 kg is moving horizontally
with a velocity 50 m/s. A mass of 250 kg is
added. Find the final velocity
View Question Equal volumes of two gases, having their
densities in the ratio of 1 : 16 exert equal
pressures on the walls of two cont
View Question A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio $$C_p/C_V$$ of the mixture is
View Question A particle executes a linear SHM with an
amplitude of 4 cm. At the mean position the
velocity of the particle is 10 cm/s
View Question The equation of a progressive wave can be given by $$y=15\sin(660\pi t-0.02\pi x)$$ cm. The frequency of the wave is
View Question A source of sound gives 5 beats per second, when sounded with another source of frequency 100 s$$^{-1}$$. The second har
View Question A charge of 0.8 C is divided into two charges Q$$_1$$ and Q$$_2$$. These are kept at a separation of 30 cm. The force on
View Question An electric dipole has a pair of equal and opposite point charges $$q$$ and $$-q$$ separated by a distance $$2x$$. The a
View Question An electric dipole is placed in a uniform electric
field with the dipole axis making an angle $$\theta$$ with
the direct
View Question Two point charges A = +3 nC and B = +1 nC are placed 5 cm apart in air. The work done to move charge B towards A by 1 cm
View Question The potential energies associated with four
orientations of an electric dipole in an electric
field are
(i) $$-5U_0$$ (i
View Question Suppose refractive index $$\alpha$$ is given as $$ \alpha = A + {B \over {{\lambda ^2}}}$$, where A and B are constants
View Question If voltage $$V=(200\pm 8)V$$ and current $$I=(20\pm0.5)A$$, then the percentage error in resistance R is
View Question A body is projected vertically upwards. The
times corresponding to height $$h$$, while
ascending and while descending ar
View Question A particle shows distance-time curve as given in
this figure. The maximum instantaneous
velocity of the particle is arou
View Question A fluid is in streamline flow across a horizontal
pipe of variable area of cross-section. For this
which of the followin
View Question Two capacitors $$C_1$$ and $$C_2$$ are charged to 120 V
and 200 V, respectively. When they are
connected in parallel, it
View Question Point out the right statements about the validity
of Kirchhoff’s junction rule,
View Question Four particles each of the mass m are placed at
the corners of a square of side length $$l$$. The
radius of gyration of
View Question A steel wire of length 4.7 m and cross-sectional area $$3.0\times10^{-5}$$ m$$^2$$ stretches by the same amount as a cop
View Question The masses of 200 g and 300 g are attached to
the 20 cm and 70 cm marks of a light meter rod,
respectively. The moment o
View Question Two spherical bodies of masses M and 5M and
radii R and 2R are released in free space with
initial separation between th
View Question If $$P=Q=R=10\Omega$$ and $$S=20\Omega$$, then what resistance should be joined with S to balance the Wheatstone's netwo
View Question To the potentiometer wire of length L and 10$$\Omega$$ resistance, a battery of emf 2.5 V and a resistance R are connect
View Question An electron moves with speed of 2 $$\times$$ 10$$^5$$ m/s along the positive x-direction in a magnetic field $$B = (\wid
View Question A horizontal overhead power line carries a
current of 90 A in East to West direction. What
is the magnitude and directio
View Question A moving coil galvanometer has 28 turns and area of coil is $$4\times 10^{-2}$$ m$$^2$$. If the magnetic field is 0.2 T,
View Question The intensity of magnetic field due to an isolated pole of strength $$m_p$$ at a point distant $$r$$ from it will be
View Question The particle that cannot be accelerated by a cyclotron is
View Question The angle which the total magnetic field of
earth makes with the surface of the earth is
called
View Question The angle of dip of at a place where horizontal
and vertical components of earth’s magnetic
field are equal is
View Question A coil of wire of a certain radius has 100 turns
and a self inductance of 15 mH. The self
inductance of a second similar
View Question A coil of 100 turns carries a current of 5 mA and
creates a magnetic flux of 10$$^{-5}$$ Wb. The
inductance is
View Question In step-up transformer, relation between number of turns in primary (N$$_P$$) and number of turns in secondary (N$$_S$$)
View Question For a series L-C-R circuit at resonance, which statement is not true?
View Question Which of the following has/have zero average
value in a plane electromagnetic wave?
View Question A convex lens is made of 3 layers of glass of 3 different materials as in the figure.
A point object is placed on its a
View Question A ray of light suffers minimum deviation in
equilateral prism P. Additional prisms Q and R
of identical shape and of sam
View Question Two identical light waves, propagating in the
same direction, have a phase difference $$\delta$$. After
they superpose t
View Question A plastic sheet (refractive index = 1 6. ) covers one
slit of a double slit arrangement for the Young’s
experiment. When
View Question A particle starts moving from point (2, 10, 1). Displacement for the particle is $$8\widehat i - 2\widehat j + \widehat
View Question