COMEDK 2021

Paper was held on
Tue, Sep 14, 2021 3:30 AM

## Chemistry

When the expansion of a gas occurs in vacuum and at constant volume, then

View Question Carbon monoxide is poisonous to human beings because

View Question Which one of the following sets of monosaccharides forms sucrose?

View Question Under which of the following condition, the gases does not follow Henry's law?

View Question An aqueous solution of X on addition of hydrogen peroxide in ice cold conditions gives blue colour to the ethereal layer

View Question Determine the specific rate constant of the reaction. If the half-life period of a first order reaction is 1402 s.

View Question Which of the following amino acid (NH$$_2$$CHRCOOH) contains polar R group?

View Question Find the correct order of C$$-$$O bond length among CO, CO$$_3^{2-}$$, CO$$_2$$.

View Question The total number of nodes are given by

View Question In the equilibrium, $$AB\rightleftharpoons A+B$$, if the equilibrium concentration of A is double, then equilibrium conc

View Question The reaction $$\mathrm{ArN_2^ + C{l^ - }\buildrel {Cu/HCl} \over
\longrightarrow ArCl + {N_2} + CuCl}$$ is called as

View Question In 3d-transmission series, which one has the least melting point?

View Question Among the following enzymes, which one is involved in the given below catalytic reaction?
$${C_6}{H_{12}}{O_6}(aq) \to 2

View Question Which of the following is correct mixture of azeotrope?

View Question Rate constant (K) of a reaction has least value at

View Question Arrange stability of the given carbon cation in decreasing order

View Question Which of the following pairs of ions in iso-electronic and iso-structural?

View Question For the equilibrium,
2NOCl(g) $$\rightleftharpoons$$ 2NO(g) + Cl$$_2$$(g),
the value of the equilibrium constant, $$K_C$

View Question Coupling reaction is an example of

View Question The oxidation number of Cr in CrO$$_5$$ which has the following structure, is

View Question Given that molar conductances for Ba(OH)$$_2$$, BaCl$$_2$$ and NH$$_4$$Cl are 523.28, 280.0 and 129.8 $$\Omega^{-1}$$ cm

View Question Xerophthalmia disease causes by which deficiency of vitamin?

View Question Find the final product for the reaction

View Question The chemical formula of Hinsberg's reagent is

View Question The increasing order of atomic radii of the following group 13 elements is

View Question The hydrocarbon that cannot be prepared effectively by Wurtz reaction

View Question Reaction
find the product B.

View Question Why, ketones and carboxylic acids have higher boiling point as compared to aldehydes?

View Question In the chemical reaction,
N$$_2$$ + 3H$$_2$$ $$\rightleftharpoons$$ 2NH$$_3$$ at equilibrium point.

View Question The change in the energy of system if 500 cal of heat energy are added to a system and system does 350 cal of work on th

View Question Which of the following is most stable?

View Question Which type of ligand is EDTA?

View Question Which of the following is correct order of their increasing boiling points?

View Question The specific conductivity of a solution containing 1.0 g of anhydrous BaCl$$_2$$ in 200 cm$$^3$$ of the solution has bee

View Question For the reaction 2N$$_2$$O$$_5$$ $$\to$$ 4NO$$_2$$ + O$$_2$$, rate constant $$k$$ is 4.48 $$\times$$ 10$$^{-5}$$ s$$^{-1

View Question Calculate the difference between C$$_p$$ and C$$_V$$ for 10 moles of an ideal gas

View Question What would be the molarity of one litre solution of 22.2 g of CaCl$$_2$$ ?

View Question For decolourisation of 1 mole of KMnO$$_4$$, the moles of H$$_2$$O$$_2$$ required is

View Question What is the IUPAC name of following compound?

View Question Find the compound which have both polar and non-polar covalent bonds.

View Question What is the product formed when benzene react with CO and HCl in presence of anhydrous AlCl$$_3$$?

View Question Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?

View Question The value of $$\Delta G^\circ$$ for the phosphorylation of glucose in glycolysis is 13.8 kJ/mol. The value of $$K_C$$ at

View Question The Lyman series of hydrogen spectrum lies in which region

View Question The correct IUPAC name of the coordination compound K$$_3$$[Fe(CN)$$_5$$NO] is

View Question ## Mathematics

Shade the feasible region for the inequations $$x+y\ge2,2x+3y\le6,x\ge0,y\ge0$$ in a rough figure.

View Question The maximum value of $$x+y$$ subject to $$2x+3y\le6,x\ge0,y\ge0$$ is

View Question Write the solution of the following LPP
Maximize $$Z=x+y$$
Subject to $$3x+4y\le12,x\ge0,y\ge0$$.
Which point the value

View Question The vector that must be added to $$\widehat i - 3\widehat j + 2\widehat k$$ and $$3\widehat i + 6\widehat j - 7\widehat

View Question If |a| = 8, |b| = 3 and |a $$\times$$ b| = 12, then find the angle between a and b.

View Question If for $$a = 2\widehat i + 3\widehat j + \widehat k,b = \widehat i - 2\widehat j + \widehat k$$ and $$c = - 3\widehat i

View Question If for any 2 $$\times$$ 2 square matrix A, A (adj A) = $$\left[ {\matrix{
8 & 0 \cr
0 & 8 \cr
} } \right]$$,

View Question If matrix $$A = \left[ {\matrix{
2 & { - 2} \cr
{ - 2} & 2 \cr
} } \right]$$ and $${A^2} = pA$$, then the va

View Question If $$A\,(adj\,A) = \left[ {\matrix{
{ - 2} & 0 & 0 \cr
0 & { - 2} & 0 \cr
0 & 0 & { - 2} \cr
} } \right

View Question The coefficients a, b and c of the quadratic equation, $$ax^2+bx+c=0$$ are obtained by throwing a dice three times. The

View Question $${8^{3{{\log }_8}5}}$$ is equal to

View Question The equation of normal to the curve $$y = {(1 + x)^y} + {\sin ^{ - 1}}({\sin ^2}x)$$ at $$x = 0$$ is

View Question If $$L = \mathop {\lim }\limits_{x \to 0} {{a - \sqrt {{a^2} - {x^2}} - {{{x^2}} \over 4}} \over {{x^4}}},a > 0$$. If L

View Question What will be the equation of circle whose centre is (1, 2) and touches X-axis?

View Question The approximate value of $$f(5.001)$$, where $$f(x)=x^3-7x^2+15$$ is

View Question Find the centre and radius of the circle given by the equation $$2{x^2} + 2{y^2} + 3x + 4y + {9 \over 8} = 0$$.

View Question Find the maximum value of $$f(x) = {1 \over {4{x^2} + 2x + 1}}$$.

View Question If $$f(x) = \left\{ {\matrix{
{ax + 3,} & {x \le 2} \cr
{{a^2}x - 1} & {x > 2} \cr
} } \right.$$, then the v

View Question The value of $$\mathop {\lim }\limits_{x \to 0} \left( {{{{a^x} + {b^x} + {c^x}} \over 3}} \right),(a,b,c > 0)$$ is

View Question What will be the equation of the circle whose centre is (1, 2) and which passes through the point (4, 6)?

View Question The line $${{x - 2} \over 3} = {{y - 3} \over 4} = {{z - 4} \over 5}$$ is parallel to the plane

View Question The equation of a plane passing through the line of intersection of the planes $$x+2y+3z=2,x-y+z=3$$ and at a distance $

View Question The angle between the lines $$2x=3y=-z$$ and $$6x=-y=-4z$$ is

View Question The point of intersection of the lines $${{x - 1} \over 2} = {{y - 2} \over 3} = {{z - 3} \over 4}$$ and $${{x - 4} \ove

View Question $$\int {{{{2^x}} \over {\sqrt {1 - {4^x}} }}dx} $$ is equal to

View Question $$\int_{ - \pi /2}^{\pi /2} {\sin xdx} $$

View Question Integral of $$\int {{{dx} \over {{x^2}{{[1 + {x^4}]}^{3/4}}}}} $$.

View Question Three of the six vertices of a regular hexagon are chosen at random. The probability that the triangle with three vertic

View Question Five persons A, B, C, D and E are in queue of a shop. The probability that A and E are always together, is

View Question If A, B and C are mutually exclusive and exhaustive events of a random experiment such that $$P(B) = {3 \over 2}P(A)$$ a

View Question A student answers a multiple choice question with 5 alternatives, of which exactly one is correct. The probability that

View Question If x and y are acute angles, such that $$\cos x + \cos y = {3 \over 2}$$ and $$\sin x + \sin y = {3 \over 4}$$, then $$\

View Question The expression $${{\tan A} \over {1 - \cot A}} + {{\cot A} \over {1 - \tan A}}$$ can be written as

View Question If $$\sin 2x = 4\cos x$$, then x is equal to

View Question If $$f(x)$$ satisfies the relation $$2f(x) + f(1 - x) = {x^2}$$ for all real x, then $$f(x)$$ is

View Question If A = {1, 2, 5, 6} and B = {1, 2, 3}, then (A $$\times$$ B) $$\cap$$ (B $$\times$$ A) is equal to

View Question Total number of elements in the power set of A containing 15 elements is

View Question What is the argument of the complex number $${{(1 + i)(2 + i)} \over {3 - i}}$$, where $$i = \sqrt { - 1} $$ ?

View Question Evaluate $${\left[ {{i^{18}} + {{\left( {{1 \over i}} \right)}^{25}}} \right]^3}$$.

View Question If $${(\sqrt 3 + i)^{100}} = {2^{99}}(a + ib)$$, then $${a^2} + {b^2}$$ is equal to

View Question Using mathematical induction, the numbers $${a_n}$$'s are defined by $${a_0} = 1,{a_{n + 1}} = 3{n^2} + n + {a_n},(n \ge

View Question If $$49^n+16n+P$$ is divisible by 64 for all $$n\in N$$, then the least negative integral value of P is

View Question $${2^{3n}} - 7n - 1$$ is divisible by

View Question The solution of the differential equation $${\sec ^2}x\tan ydx + {\sec ^2}y\tan xdy = 0$$ is

View Question The solution of the differential equation $$y{{dy} \over {dx}} = x\left[ {{{{y^2}} \over {{x^2}}} + {{\phi \left( {{{{y^

View Question The solution of the differential equation $$(1 + {y^2}) + (x - {e^{{{\tan }^{ - 1}}y}}){{dy} \over {dx}} = 0$$ is

View Question The value of $$1\,.\,1! + 2\,.\,2! + 3\,.\,3! + \,...\, + \,n\,.\,n!$$ is

View Question The sum of the series $$(1 + 2) + (1 + 2 + {2^2}) + (1 + 2 + {2^2} + {2^3}) + ....$$ upto $$n$$ terms is

View Question If a, b, c are in A.P., $$b-a,c-b$$ and a are in G.P., then a : b : c is

View Question The number of triangles which can be formed by using the vertices of a regular polygon of $$(n+3)$$ sides is 220. Then,

View Question Out of 8 given points, 3 are collinear. How many different straight lines can be drawn by joining any two points from th

View Question How many numbers greater than 40000 can be formed from the digits 2, 4, 5, 5, 7?

View Question If a polygon of n sides has 275 diagonals, then n is equal to

View Question If two pairs of lines $$x^2-2mxy-y^2=0$$ and $$x^2-2nxy-y^2=0$$ are such that one of them represents the bisector of the

View Question The distance of the point (1, 2) from the line $$x+y+5=0$$ measured along the line parallel to $$3x-y=7$$ is equal to

View Question The slopes of the lines, which make an angle 45$$^\circ$$ with the line $$3x-y=-5$$, are

View Question If 3 and 4 are intercepts of a line L = 0, then the distance of L $$\equiv$$ 0 from the origin is

View Question Number of terms in the binomial expansion of $$(x+a)^{53}+(x-a)^{53}$$ is

View Question The coefficient of $$x^{10}$$ in the expansion of $$1+(1+x)+...+(1+x)^{20}$$ is

View Question Middle term in the expansion of $${\left( {{x^2} + {1 \over {{x^2}}} + 2} \right)^n}$$ is

View Question ## Physics

The Lyman series of a hydrogen atom belongs
in which category

View Question Insulators can be charged by which of the following process?

View Question In an adiabatic process with the ratio of two specific heat, $$\gamma=\frac{3}{2}$$, pressure is increased by $$\frac{2}

View Question Two converging lenses of focal length 20 cm and 40 cm are placed in contact. The effective power of the combination is

View Question The formula of capacitative reactance is

View Question Which graph shows the correct $$v$$ - $$x$$ graph of a freely falling body?

View Question The displacement $$x$$ of a particle varies with time $$t$$, $$x=ae^{-pt}+be^{qt}$$, where a, b, p and q are positive co

View Question Which of the following quantity represents the dimensions of momentum?

View Question The angle of projection with the horizontal in terms of maximum height attained and horizontal range is given by

View Question For the same resonant frequency, if L is changed from L to $${L \over 3}$$, then capacitance should change from C to

View Question The velocity of the proton is one-fourth the velocity of the electron. What is the ratio of the de-Broglie wavelength of

View Question For an ideal gas, coefficient of volume expansion is given by

View Question Which of the following is not a green house gas?

View Question Two particles of masses $$m_1=m,m_2=2m$$ and charges $$q_1=q,q_2=2q$$ entered into uniform magnetic field. Find $$F_1/F_

View Question Work done in moving a charge of 25C is 50 J. Calculate potential difference, between two points.

View Question The correct arrangement in increasing order of wavelength of X-rays, UV rays, microwave is

View Question What is the electric field near infinite plane sheet of charge density $$\sigma$$ ?

View Question Which of the following waves are used to treatment of muscles ache?

View Question Find the logic gate, when both the inputs are high but the output is low and vice-versa.

View Question What is the minimum band-gap of the LED diode?

View Question The displacement of a wave is given by
$$y = 20\cos (\omega t + 4z)$$
The amplitude of the given wave is

View Question If frequencies are $$(\nu-1)$$ and $$(\nu+2)$$, then find the value of beats.

View Question The function $$y = \log \omega t$$ can represent

View Question Two spring of force constant $$k_1$$ and $$k_2$$ are configured as the figure given below
The angular frequency of this

View Question The resistance of a wire is R ohm. If it is melted and stretched to n times its original length, its new resistance will

View Question An unpolarised beam of intensity I$$_0$$ is incident on a pair of nicols making an angle of 60$$^\circ$$ with each other

View Question The collision of the molecules of an ideal gas is taken as

View Question The average energy associated with a monoatomic molecule is

View Question For the given electrical arrangement, what is the value of current I?

View Question If an electron in hydrogen atom jumps from an orbit of level $$n=3$$ to an orbit at level $$n=2$$, emitted radiation has

View Question Within the elastic limit, the corresponding stress is known as

View Question A wire is stretched to double of its length. The strain is

View Question Kepler's second law of planetary motion corresponds to

View Question A constant potential energy of a satellite is given as
$$\mathrm{PE}=r(\mathrm{KE})$$
whee, PE = potential energy
and KE

View Question A long solenoid has 20 turns cm$$^{-1}$$. The current necessary to produce a magnetic field of 20 mT inside the solenoid

View Question A constant current flows from A to B as shown in the figure. What is the direction of current in the circle?

View Question According to Pascal's law, pressure in a fluid at rest is the same at all points, if

View Question The surface tension of a liquid at its boiling point

View Question Centre of mass of the given system of particles will be at

View Question Newton's second law of rotational motion of a system particles having angular momentum L is given by

View Question The motion of a particle of mass $$m$$ is described by $$y = ut + g{t^2}$$. The force acting on the particle will be

View Question When a car of mass $$m$$ is moving with speed $$v$$ along a circle of radius $$r$$ on a level road, the centripetal forc

View Question Ba-122 has half-life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. It i

View Question When the speed of light becomes $$\frac{2}{3}$$ of its present value, then the energy released in a given atomic explosi

View Question What should be the value of self-inductance of an inductor that should be connected to 220 V 50 Hz supply, so that a max

View Question The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and

View Question Two masses of 1g and 9g are moving with equal kinetic energy. The ratio of magnitude of their momentum is

View Question When two bodies collide with each other such that their kinetic energy remains constant. Their collision is said to be

View Question For motion under central forces, which quantity will be conserved?

View Question Which of the following statement is incorrect?

View Question If impedance is $$\sqrt3$$ times of resistance, then find phase difference.

View Question A bar magnet is oscillating in the earth's magnetic field with a period T. What happens to its period and motion, if its

View Question The relative permeability of iron is 6000. Its magnetic susceptibility is

View Question Which of the following technique is not used for measuring small time intervals?

View Question The relative errors in the measurement of two lengths 1.02 cm $$\pm$$ 0.01 cm and 9.89 cm $$\pm$$ 0.01 cm is

View Question In Young's double slit experiment with sodium vapour lamp of wavelength 589 nm and slit 0.589 mm apart, the half angular

View Question From the figure describing photoelectric effect, we may infer correctly that

View Question Carnot cycle of an engine is given below
Total work done by the gas in one cycle is

View Question