Chemistry
1. During the extraction of gold the following reactions take place
$$\mathrm{Au + C{N^ - } + {H_2}O\buildrel {{O_2}} \over 2. The number of gram molecules of chlorine in $$6.02\times10^{25}$$ hydrogen chloride molecules is 3. Graphite is a soft solid lubricant extremely
difficult to melt. The reason for this anomalous
behaviour is that, graphit 4. Paracetamol is a/an 5. Which one of the following has maximum
number of atoms of oxygen? 6. Which one of the following shows functional
isomerism? 7. In the ionic equation,
$$\mathrm{BiO_3^-+6H^++xe^-\rightarrow Bi^{3+}+3H_2O}$$,
the value of x is 8. Molarity of a given orthophosphoric acid
solution is 3M. It’s normality is 9. Acidified sodium fusion extract on addition of
ferric chloride solution gives blood red
colouration which confirms the p 10. A body of mass 10 mg is moving with a velocity of 100 ms$$^{-1}$$. The wavelength of de-Broglie wave associated with it 11. Mg$$^{2+}$$ is isoelectronic with 12. Gram molecular volume of oxygen at STP is 13. Presence of halogen in organic compounds can be detected using 14. The electronic configuration of Cr$$^{3+}$$ is 15. The mass of a metal, with equivalent mass 31.75, which would combine with 8 g of oxygen is 16. Benzene reacts with chlorine in sunlight to give a final product 17. In the periodic table metals usually used as catalysts belong to 18. Dalton’s law of partial pressures is applicable to
which one of the following systems? 19. The general formula of a cycloalkene is 20. In acetylene molecule, between the carbon atoms there are 21. Denatured alcohol is 22. During the formation of a chemical bond 23. One mole of oxygen at 273 K and one mole of
sulphur dioxide at 546 K are taken in two
separate containers, then 24. +I-effect is shown by 25. Formation of coloured solution is possible,
when metal ion in the compound contains 26. Which of the following is an intensive property? 27. Hofmann’s bromamide reaction is to convert 28. IUPAC name of Na$$_3$$[Co(NO$$_2$$)$$_6$$] is 29. Thermodynamic standard conditions of
temperature and pressure are 30. How many chiral carbon atoms are present in
2, 3, 4-trichloropentane ? 31. The number of unidentate ligands in the
complex ion is called 32. $$2S{O_2}(g) + {O_2}(g)\buildrel {{V_2}{O_5}} \over
\rightleftharpoons $$ is an example for 33. The amino acid which is not optically active is 34. For a stable molecule the value of bond order
must be 35. Which one of the following is a second order
reaction? 36. According to Baeyer's strain theory which is highly stable? 37. The number of antibonding electron pairs in O$$_2^{2-}$$ molecular ion on the basis of molecular orbital theory is
[Atom 38. Hydroxyl ion concentration of 1M HCl is 39. Geometrical isomerism is shown by 40. The oxidation state of iron in K$$_4$$[Fe(CN)$$_6$$] is, 41. In which of the following process, a maximum
increase in entropy is observed? 42. Decomposition of benzene diazonium chloride by using Cu$$_2$$Cl$$_2$$/HCl to form chlorobenzene is 43. Which complex cannot ionise in solution? 44. Consider the reaction,
C(s) + O$$_2$$(g) $$\rightarrow$$ CO$$_2$$(g) + 393.5 kJ
The signs of $$\Delta H,\Delta S$$ and $ 45. The product formed when hydroxylamine
condenses with a carbonyl compound is called 46. Which of the following forms a colourless
solution in aqueous medium? 47. When a sulphur sol is evaporated, sulphur is
obtained. On mixing with water, sulphur sol is
not formed. The sol is 48. An alkyl halide reacts with alcoholic ammonia in
a sealed tube, the product formed will be 49. When conc. H$$_2$$SO$$_4$$ is heated with P$$_2$$O$$_5$$, the acid is converted into 50. Entropy of the universe is 51. Which of the following salts on being dissolved in water gives pH > 7 at 25$$^\circ$$C ? 52. The reagent used in Clemmenson's reduction is 53. When KBr is dissolved in water, K$$^+$$ ions are 54. The noble gas mixture is cooled in a coconut bulb
at 173 K. The gases that are not adsorbed are 55. The volume of 10N and 4N HCl required to
make 1 litre of 7N HCl are 56. A metal present in insulin is 57. Carbon forms two oxides which have different
compositions. The equivalent mass of which
remains constant? 58. Maximum number of molecules of CH$$_3$$I that can react with a molecule of CH$$_3$$NH$$_2$$ are 59. Ellingham diagram represents a graph of 60. Identify the ore not containing iron
Mathematics
1. $${7^{2{{\log }_7}5}}$$ is equal to 2. In the group $$(G\,{ \otimes _{15}})$$, where $$G = \{ 3,6,9,12\} $$, $${ \otimes _{15}}$$ is multiplication modulo 15, 3. A group (G *) has 10 elements. The minimum number of elements of G, which are their own inverses is 4. If a and b are vectors such that $$|a + b|=|a-b|$$, then the angle between a and b is 5. $${{3{x^2} + 1} \over {{x^2} - 6x + 8}}$$ is equal to 6. If $$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 7. OA and BO are two vectors of magnitudes 5 and 6 respectively. If $$\angle BOA=60^\circ$$, then OA . OB is equal to 8. A vector perpendicular to the plane containing the points $$A(1, - 1,2),B(2,0, - 1),C(0,2,1)$$ is 9. $${1 \over {2\,.\,5}} + {1 \over {5\,.\,8}} + {1 \over {8\,.\,11}} + .............
+ {1 \over {(3n - 1)(3n + 2)}} = $$ 10. The ninth term of the expansion $${\left( {3x - {1 \over {2x}}} \right)^8}$$ is 11. If $$A = \left[ {\matrix{
1 & { - 1} & 1 \cr
2 & 1 & { - 3} \cr
1 & 1 & 1 \cr
} } \right],10B = \left[ 12. If $$A = \left[ {\matrix{
0 & x & {16} \cr
x & 5 & 7 \cr
0 & 9 & x \cr
} } \right]$$ is singular, then 13. If $$A = \left[ {\matrix{
1 & { - 2} & 2 \cr
0 & 2 & { - 3} \cr
3 & { - 2} & 4 \cr
} } \right]$$, then 14. If $$f:R \to R$$ is defined by $$f(x) = |x|$$, then 15. The value of $$\left| {\matrix{
x & p & q \cr
p & x & q \cr
p & q & x \cr
} } \right|$$ is 16. The number of common tangents to the circles $$x^2+y^2=4$$ and $$x^2+y^2-6x-8y-24=0$$ is, 17. If $$3x+y+k=0$$ is a tangent to the circle $$x^2+y^2=10$$, the values of k are 18. The negation of the proposition “If 2 is prime,
then 3 is odd” is 19. The equation to two circles which touch the
Y-axis at (0, 3) and make an intercept of 8 units
on X-axis are 20. The orthocentre of the triangle with vertices A(0, 0), B(0, 3/2), C($$-$$5, 0) is 21. $${x^2} + {y^2} - 6x - 6y + 4 = 0$$, $${x^2} + {y^2} - 2x - 4y + 3 = 0$$, $${x^2} + {y^2} + 2kx + 2y + 1 = 0$$. If the r 22. If the circles $${x^2} + {y^2} - 2x - 2y - 7 = 0$$ and $${x^2} + {y^2} + 4x + 2y + k = 0$$ cut orthogonally, then the le 23. The coordinates of the foot of the perpendicular drawn from the point (3, 4) on the line $$2x+y-7=0$$ is 24. The area enclosed by the pair of lines $$xy=0$$, the line $$x-4=0$$ and $$y+5=0$$ is 25. If the area of the auxillary circle of the ellipse $${{{x^2}} \over {{a^2}}} + {{{y^2}} \over {{b^2}}} = 1(a > b)$$ is t 26. A graph G has m vertices of odd degree and ‘n’
vertices of even degree. Then which of the
following statements is necess 27. If p is any point on the ellipse $${{{x^2}} \over {36}} + {{{y^2}} \over {16}} = 1$$, and S and S' are the foci, then $$ 28. The value of $$\sin \left[ {2{{\cos }^{ - 1}}{{\sqrt 5 } \over 3}} \right]$$ is 29. If $${{{x^2}} \over {36}} - {{{y^2}} \over {{k^2}}} = 1$$ is a hyperbola, then which of the following statements can be 30. The focus of the parabola is 31. The solution of $${\tan ^{ - 1}}x + 2{\cot ^{ - 1}}x = {{2\pi } \over 3}$$ is 32. $${\sin ^2}17.5^\circ + \sin 72.5^\circ $$ is equal to 33. The conjugate of the complex number $${{{{(1 + i)}^2}} \over {1 - i}}$$ is 34. ABC is a triangle with $$\angle A=30^\circ$$ and BC = 10 cm. The area of the circumcircle of the triangle is
35. If $$\sin 3\theta = \sin \theta $$, how many solutions exist such that $$ - 2\pi 36. The imaginary part of $$i^i$$ is 37. The amplitude of $${(1 + i)^5}$$ is 38. ABC is a triangle, G is the centroid, D is the mid-point of BC. If A = (2, 3) and G = (7, 5), then the point D is 39. $$\mathop {\lim }\limits_{x \to 1} {{\tan ({x^2} - 1)} \over {x - 1}}$$ is equal to 40. If $$y = {2^{\log x}}$$, then $${{dy} \over {dx}}$$ is 41. If $${\sec ^{ - 1}}\left( {{{1 + x} \over {1 - y}}} \right) = a$$, then $${{dy} \over {dx}}$$ is 42. If $$y = {\cos ^2}{{3x} \over 2} - {\sin ^2}{{3x} \over 2}$$, then $${{{d^2}y} \over {d{x^2}}}$$ is 43. If the function $$f(x) = \left\{ {\matrix{
{{{1 - \cos x} \over {{x^2}}},} & {\mathrm{for}\,x \ne 0} \cr
{k,} & 44. If $$1,\omega ,{\omega ^2}$$ are the cube roots of unity, then $$(1 + \omega )(1 + {\omega ^2})(1 + {\omega ^4})(1 + {\o 45. If $${x^x} = {y^y}$$, then $${{dy} \over {dx}}$$ is 46. The point on the curve $$y^2=x$$, the tangent at which makes an angle 45$$^\circ$$ with X-axis is 47. The length of the subtangent to the curve $${x^2}{y^2} = {a^4}$$ at $$( - a,a)$$ is 48. The number of positive divisors of 252 is 49. The remainder obtained when 5124 is divided by 124 is 50. Which of the following is not a group with
respect to the given operation? 51. The range in which $$y = - {x^2} + 6x - 3$$ is increasing, is 52. The value of the integral $$\int\limits_0^{\pi /2} {({{\sin }^{100}}x - {{\cos }^{100}}x)dx} $$ is 53. OA and OB are two roads enclosing an angle of
120$$^\circ$$. X and Y start from O at the same time. X
travels along OA w 54. If $$k\int\limits_0^1 {x\,.\,f(3x)dx = \int\limits_0^3 {t\,.\,f(t)dt} } $$, then the value of $$k$$ is 55. The value of $$\int {{1 \over {1 + \cos 8x}}dx} $$ is 56. The value of $$\int {{e^x}({x^5} + 5{x^4} + 1)\,.\,dx} $$ is 57. The value of $$\int {{{{x^2} + 1} \over {{x^2} - 1}}dx} $$ is 58. The area bounded by the curve $$x=4-y^2$$ and the Y-axis is 59. The differential equation of the family of
straight lines whose slope is equal to y-intercept
is 60. The order and degree of the differential equation $${\left[ {1 + {{\left( {{{dy} \over {dx}}} \right)}^5}} \right]^{{1 \
Physics
1. Light of frequency 1015 Hz falls on a metal surface of work function 2.5 eV. The stopping potential of photoelectrons (i 2. A proton accelerated through a potential V has de-Broglie wavelength $$\lambda$$. Then, the de-Broglie wavelength of an 3. Consider a thin spherical shell of radius R
consisting of uniform surface charge density s.
The electric field at a poin 4. An electron of an atom transits from $$n_1$$ to $$n_2$$. In which of the following maximum frequency of photon will be e 5. 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 6. Two radioactive materials X$$_1$$ and X$$_2$$ have decay constant 5$$\lambda$$ and $$\lambda$$, respectively. If initial 7. 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 8. 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 9. When a $$p$$-$$n$$ junction diode is connected in forward bias, its barrier potential 10. Ground waves have wavelength 11. A ball floats on the surface of water in a
container exposed to the atmosphere. When the
container is covered and the ai 12. 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 13. A compound slab is made of two parallel plates
of copper and brass of the same thickness and
having thermal conductiviti 14. In mm$$^3$$ of a gas is compressed at 1 atmospheric pressure and temperature 27$$^\circ$$C to 627$$^\circ$$C. What is th 15. If sink is at a temperature of $$-39\Upsilon$$C and source at 0$$^\circ$$C, then efficiency will be 16. Which of the following laws of Physics is valid
across all domains of nature? 17. A particle of mass m is moving in a horizontal
circle of radius R under a centripetal force equal
to $$-\frac{A}{R^2}$$ 18. 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 19. 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. 20. 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 21. Equal volumes of two gases, having their
densities in the ratio of 1 : 16 exert equal
pressures on the walls of two cont 22. A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio $$C_p/C_V$$ of the mixture is 23. 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 24. 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 25. A source of sound gives 5 beats per second, when sounded with another source of frequency 100 s$$^{-1}$$. The second har 26. 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 27. An electric dipole has a pair of equal and opposite point charges $$q$$ and $$-q$$ separated by a distance $$2x$$. The a 28. An electric dipole is placed in a uniform electric
field with the dipole axis making an angle $$\theta$$ with
the direct 29. 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 30. The potential energies associated with four
orientations of an electric dipole in an electric
field are
(i) $$-5U_0$$ (i 31. Suppose refractive index $$\alpha$$ is given as $$ \alpha = A + {B \over {{\lambda ^2}}}$$, where A and B are constants 32. If voltage $$V=(200\pm 8)V$$ and current $$I=(20\pm0.5)A$$, then the percentage error in resistance R is 33. A body is projected vertically upwards. The
times corresponding to height $$h$$, while
ascending and while descending ar 34. A particle shows distance-time curve as given in
this figure. The maximum instantaneous
velocity of the particle is arou 35. A fluid is in streamline flow across a horizontal
pipe of variable area of cross-section. For this
which of the followin 36. Two capacitors $$C_1$$ and $$C_2$$ are charged to 120 V
and 200 V, respectively. When they are
connected in parallel, it 37. Point out the right statements about the validity
of Kirchhoff’s junction rule, 38. Four particles each of the mass m are placed at
the corners of a square of side length $$l$$. The
radius of gyration of 39. 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 40. 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 41. Two spherical bodies of masses M and 5M and
radii R and 2R are released in free space with
initial separation between th 42. If $$P=Q=R=10\Omega$$ and $$S=20\Omega$$, then what resistance should be joined with S to balance the Wheatstone's netwo 43. To the potentiometer wire of length L and 10$$\Omega$$ resistance, a battery of emf 2.5 V and a resistance R are connect 44. An electron moves with speed of 2 $$\times$$ 10$$^5$$ m/s along the positive x-direction in a magnetic field $$B = (\wid 45. A horizontal overhead power line carries a
current of 90 A in East to West direction. What
is the magnitude and directio 46. A moving coil galvanometer has 28 turns and area of coil is $$4\times 10^{-2}$$ m$$^2$$. If the magnetic field is 0.2 T, 47. The intensity of magnetic field due to an isolated pole of strength $$m_p$$ at a point distant $$r$$ from it will be 48. The particle that cannot be accelerated by a cyclotron is 49. The angle which the total magnetic field of
earth makes with the surface of the earth is
called 50. The angle of dip of at a place where horizontal
and vertical components of earth’s magnetic
field are equal is 51. A coil of wire of a certain radius has 100 turns
and a self inductance of 15 mH. The self
inductance of a second similar 52. A coil of 100 turns carries a current of 5 mA and
creates a magnetic flux of 10$$^{-5}$$ Wb. The
inductance is 53. In step-up transformer, relation between number of turns in primary (N$$_P$$) and number of turns in secondary (N$$_S$$) 54. For a series L-C-R circuit at resonance, which statement is not true? 55. Which of the following has/have zero average
value in a plane electromagnetic wave? 56. A convex lens is made of 3 layers of glass of 3 different materials as in the figure.
A point object is placed on its a 57. A ray of light suffers minimum deviation in
equilateral prism P. Additional prisms Q and R
of identical shape and of sam 58. Two identical light waves, propagating in the
same direction, have a phase difference $$\delta$$. After
they superpose t 59. A plastic sheet (refractive index = 1 6. ) covers one
slit of a double slit arrangement for the Young’s
experiment. When 60. A particle starts moving from point (2, 10, 1). Displacement for the particle is $$8\widehat i - 2\widehat j + \widehat
1
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0
A proton accelerated through a potential V has de-Broglie wavelength $$\lambda$$. Then, the de-Broglie wavelength of an $$\alpha$$-particle, when accelerated through the same potential V is
A
$$\frac{\lambda}{2}$$
B
$$\frac{\lambda}{\sqrt2}$$
C
$$\frac{\lambda}{2\sqrt2}$$
D
$$\frac{\lambda}{8}$$
2
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0
Consider a thin spherical shell of radius R consisting of uniform surface charge density s. The electric field at a point of distance x from its centre and outside the shell is
A
inversely proportional to $$s$$
B
directly proportional to $$x^2$$
C
directly proportional to $$R$$
D
inversely proportional to $$x^2$$
3
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0
An electron of an atom transits from $$n_1$$ to $$n_2$$. In which of the following maximum frequency of photon will be emitted?
A
$$n_1=1$$ to $$n_2=2$$
B
$$n_1=2$$ to $$n_2=1$$
C
$$n_1=2$$ to $$n_2=6$$
D
$$n_1=6$$ to $$n_2=2$$
4
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0
Two protons are kept at a separation of 40 $$\mathop A\limits^o $$. F$$_n$$ is the nuclear force and F$$_e$$ is the electrostatic force between them. Then,
A
$$F_n< < F_e$$
B
$$F_n\approx F_e$$
C
$$F_n> > F_e$$
D
$$F_n= F_e$$
Paper analysis
Total Questions
Chemistry
60
Mathematics
60
Physics
60
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