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

When the expansion of a gas occurs in vacuum and at constant volume, then
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Carbon monoxide is poisonous to human beings because
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Which one of the following sets of monosaccharides forms sucrose?
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Under which of the following condition, the gases does not follow Henry's law?
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An aqueous solution of X on addition of hydrogen peroxide in ice cold conditions gives blue colour to the ethereal layer
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Determine the specific rate constant of the reaction. If the half-life period of a first order reaction is 1402 s.
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Sodium metal crystallises in a body centred cubic lattice with a unit cell edge of 4.29 $$\mathop A\limits^o $$. The rad
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Which of the following amino acid (NH$$_2$$CHRCOOH) contains polar R group?
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Find the correct order of C$$-$$O bond length among CO, CO$$_3^{2-}$$, CO$$_2$$.
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The total number of nodes are given by
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In the equilibrium, $$AB\rightleftharpoons A+B$$, if the equilibrium concentration of A is double, then equilibrium conc
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Which of the following is used as a drug to reduce fever?
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The reaction $$\mathrm{ArN_2^ + C{l^ - }\buildrel {Cu/HCl} \over \longrightarrow ArCl + {N_2} + CuCl}$$ is called as
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In 3d-transmission series, which one has the least melting point?
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Among the following enzymes, which one is involved in the given below catalytic reaction? $${C_6}{H_{12}}{O_6}(aq) \to 2
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Which of the following is correct mixture of azeotrope?
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Rate constant (K) of a reaction has least value at
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Arrange stability of the given carbon cation in decreasing order
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Which of the following pairs of ions in iso-electronic and iso-structural?
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How much part of any corner atom actually belongs to a particular unit cell?
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For the equilibrium, 2NOCl(g) $$\rightleftharpoons$$ 2NO(g) + Cl$$_2$$(g), the value of the equilibrium constant, $$K_C$
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Arrange the following artificial Sweetening agents in order of increasing sweetness. Aspartame, Saccharin, Sucralose, Al
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Coupling reaction is an example of
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The oxidation number of Cr in CrO$$_5$$ which has the following structure, is
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Identify the pair of gases that have equal rates of diffusion
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The reducing agent which is used to reduce iron oxide in blast furnace is
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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
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Xerophthalmia disease causes by which deficiency of vitamin?
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Find the final product for the reaction
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The melting of ice
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Which of the following options represents the correct composition of dettol?
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The chemical formula of Hinsberg's reagent is
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The increasing order of atomic radii of the following group 13 elements is
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Which of the following colloids resemble to the true solutions?
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The hydrocarbon that cannot be prepared effectively by Wurtz reaction
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Reaction find the product B.
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Why, ketones and carboxylic acids have higher boiling point as compared to aldehydes?
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The vacant space in bcc lattice cell is
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In the chemical reaction, N$$_2$$ + 3H$$_2$$ $$\rightleftharpoons$$ 2NH$$_3$$ at equilibrium point.
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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
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Which of the following is not an antacid?
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Which of the following is most stable?
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Which type of ligand is EDTA?
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The density of a gas A is thrice that of a gas B at the same temperature. The molecular weight of gas B is twice that of
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Which of the following is correct order of their increasing boiling points?
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The specific conductivity of a solution containing 1.0 g of anhydrous BaCl$$_2$$ in 200 cm$$^3$$ of the solution has bee
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For the reaction 2N$$_2$$O$$_5$$ $$\to$$ 4NO$$_2$$ + O$$_2$$, rate constant $$k$$ is 4.48 $$\times$$ 10$$^{-5}$$ s$$^{-1
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Calculate the difference between C$$_p$$ and C$$_V$$ for 10 moles of an ideal gas
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Which of the following particulate matter is emitted from vehicles?
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Arrange the hydrides of group 15 in correct decreasing order of reducing nature.
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What would be the molarity of one litre solution of 22.2 g of CaCl$$_2$$ ?
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For decolourisation of 1 mole of KMnO$$_4$$, the moles of H$$_2$$O$$_2$$ required is
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What is the IUPAC name of following compound?
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Find the compound which have both polar and non-polar covalent bonds.
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What is the product formed when benzene react with CO and HCl in presence of anhydrous AlCl$$_3$$?
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Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?
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The value of $$\Delta G^\circ$$ for the phosphorylation of glucose in glycolysis is 13.8 kJ/mol. The value of $$K_C$$ at
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The Lyman series of hydrogen spectrum lies in which region
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The correct IUPAC name of the coordination compound K$$_3$$[Fe(CN)$$_5$$NO] is
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Which of the following conditions are favourable for chemisorption?
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Mathematics

Shade the feasible region for the inequations $$x+y\ge2,2x+3y\le6,x\ge0,y\ge0$$ in a rough figure.
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The maximum value of $$x+y$$ subject to $$2x+3y\le6,x\ge0,y\ge0$$ is
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Write the solution of the following LPP Maximize $$Z=x+y$$ Subject to $$3x+4y\le12,x\ge0,y\ge0$$. Which point the value
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The vector that must be added to $$\widehat i - 3\widehat j + 2\widehat k$$ and $$3\widehat i + 6\widehat j - 7\widehat
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If |a| = 8, |b| = 3 and |a $$\times$$ b| = 12, then find the angle between a and b.
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If for $$a = 2\widehat i + 3\widehat j + \widehat k,b = \widehat i - 2\widehat j + \widehat k$$ and $$c = - 3\widehat i
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If for any 2 $$\times$$ 2 square matrix A, A (adj A) = $$\left[ {\matrix{ 8 & 0 \cr 0 & 8 \cr } } \right]$$,
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If matrix $$A = \left[ {\matrix{ 2 & { - 2} \cr { - 2} & 2 \cr } } \right]$$ and $${A^2} = pA$$, then the va
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If $$A\,(adj\,A) = \left[ {\matrix{ { - 2} & 0 & 0 \cr 0 & { - 2} & 0 \cr 0 & 0 & { - 2} \cr } } \right
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The coefficients a, b and c of the quadratic equation, $$ax^2+bx+c=0$$ are obtained by throwing a dice three times. The
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$${8^{3{{\log }_8}5}}$$ is equal to
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The equation of normal to the curve $$y = {(1 + x)^y} + {\sin ^{ - 1}}({\sin ^2}x)$$ at $$x = 0$$ is
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If $$L = \mathop {\lim }\limits_{x \to 0} {{a - \sqrt {{a^2} - {x^2}} - {{{x^2}} \over 4}} \over {{x^4}}},a > 0$$. If L
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What will be the equation of circle whose centre is (1, 2) and touches X-axis?
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The approximate value of $$f(5.001)$$, where $$f(x)=x^3-7x^2+15$$ is
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Find the centre and radius of the circle given by the equation $$2{x^2} + 2{y^2} + 3x + 4y + {9 \over 8} = 0$$.
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Find the maximum value of $$f(x) = {1 \over {4{x^2} + 2x + 1}}$$.
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If $$f(x) = \left\{ {\matrix{ {ax + 3,} & {x \le 2} \cr {{a^2}x - 1} & {x > 2} \cr } } \right.$$, then the v
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The value of $$\mathop {\lim }\limits_{x \to 0} \left( {{{{a^x} + {b^x} + {c^x}} \over 3}} \right),(a,b,c > 0)$$ is
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What will be the equation of the circle whose centre is (1, 2) and which passes through the point (4, 6)?
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The line $${{x - 2} \over 3} = {{y - 3} \over 4} = {{z - 4} \over 5}$$ is parallel to the plane
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The equation of a plane passing through the line of intersection of the planes $$x+2y+3z=2,x-y+z=3$$ and at a distance $
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The angle between the lines $$2x=3y=-z$$ and $$6x=-y=-4z$$ is
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The point of intersection of the lines $${{x - 1} \over 2} = {{y - 2} \over 3} = {{z - 3} \over 4}$$ and $${{x - 4} \ove
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$$\int {{{{2^x}} \over {\sqrt {1 - {4^x}} }}dx} $$ is equal to
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$$\int_{ - \pi /2}^{\pi /2} {\sin xdx} $$
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Integral of $$\int {{{dx} \over {{x^2}{{[1 + {x^4}]}^{3/4}}}}} $$.
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Three of the six vertices of a regular hexagon are chosen at random. The probability that the triangle with three vertic
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Five persons A, B, C, D and E are in queue of a shop. The probability that A and E are always together, is
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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
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A student answers a multiple choice question with 5 alternatives, of which exactly one is correct. The probability that
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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 $$\
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The expression $${{\tan A} \over {1 - \cot A}} + {{\cot A} \over {1 - \tan A}}$$ can be written as
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If $$\sin 2x = 4\cos x$$, then x is equal to
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If $$f(x)$$ satisfies the relation $$2f(x) + f(1 - x) = {x^2}$$ for all real x, then $$f(x)$$ is
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If A = {1, 2, 5, 6} and B = {1, 2, 3}, then (A $$\times$$ B) $$\cap$$ (B $$\times$$ A) is equal to
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Total number of elements in the power set of A containing 15 elements is
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What is the argument of the complex number $${{(1 + i)(2 + i)} \over {3 - i}}$$, where $$i = \sqrt { - 1} $$ ?
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Evaluate $${\left[ {{i^{18}} + {{\left( {{1 \over i}} \right)}^{25}}} \right]^3}$$.
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If $${(\sqrt 3 + i)^{100}} = {2^{99}}(a + ib)$$, then $${a^2} + {b^2}$$ is equal to
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Using mathematical induction, the numbers $${a_n}$$'s are defined by $${a_0} = 1,{a_{n + 1}} = 3{n^2} + n + {a_n},(n \ge
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If $$49^n+16n+P$$ is divisible by 64 for all $$n\in N$$, then the least negative integral value of P is
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$${2^{3n}} - 7n - 1$$ is divisible by
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The solution of the differential equation $${\sec ^2}x\tan ydx + {\sec ^2}y\tan xdy = 0$$ is
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The solution of the differential equation $$y{{dy} \over {dx}} = x\left[ {{{{y^2}} \over {{x^2}}} + {{\phi \left( {{{{y^
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The solution of the differential equation $$(1 + {y^2}) + (x - {e^{{{\tan }^{ - 1}}y}}){{dy} \over {dx}} = 0$$ is
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The value of $$1\,.\,1! + 2\,.\,2! + 3\,.\,3! + \,...\, + \,n\,.\,n!$$ is
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The sum of the series $$(1 + 2) + (1 + 2 + {2^2}) + (1 + 2 + {2^2} + {2^3}) + ....$$ upto $$n$$ terms is
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If a, b, c are in A.P., $$b-a,c-b$$ and a are in G.P., then a : b : c is
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The number of triangles which can be formed by using the vertices of a regular polygon of $$(n+3)$$ sides is 220. Then,
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Out of 8 given points, 3 are collinear. How many different straight lines can be drawn by joining any two points from th
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How many numbers greater than 40000 can be formed from the digits 2, 4, 5, 5, 7?
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If a polygon of n sides has 275 diagonals, then n is equal to
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If two pairs of lines $$x^2-2mxy-y^2=0$$ and $$x^2-2nxy-y^2=0$$ are such that one of them represents the bisector of the
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The distance of the point (1, 2) from the line $$x+y+5=0$$ measured along the line parallel to $$3x-y=7$$ is equal to
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The slopes of the lines, which make an angle 45$$^\circ$$ with the line $$3x-y=-5$$, are
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If 3 and 4 are intercepts of a line L = 0, then the distance of L $$\equiv$$ 0 from the origin is
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Number of terms in the binomial expansion of $$(x+a)^{53}+(x-a)^{53}$$ is
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The coefficient of $$x^{10}$$ in the expansion of $$1+(1+x)+...+(1+x)^{20}$$ is
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Middle term in the expansion of $${\left( {{x^2} + {1 \over {{x^2}}} + 2} \right)^n}$$ is
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Physics

The Lyman series of a hydrogen atom belongs in which category
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Insulators can be charged by which of the following process?
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In an adiabatic process with the ratio of two specific heat, $$\gamma=\frac{3}{2}$$, pressure is increased by $$\frac{2}
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Two converging lenses of focal length 20 cm and 40 cm are placed in contact. The effective power of the combination is
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The formula of capacitative reactance is
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Which graph shows the correct $$v$$ - $$x$$ graph of a freely falling body?
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The displacement $$x$$ of a particle varies with time $$t$$, $$x=ae^{-pt}+be^{qt}$$, where a, b, p and q are positive co
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Which of the following quantity represents the dimensions of momentum?
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The angle of projection with the horizontal in terms of maximum height attained and horizontal range is given by
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For the same resonant frequency, if L is changed from L to $${L \over 3}$$, then capacitance should change from C to
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The velocity of the proton is one-fourth the velocity of the electron. What is the ratio of the de-Broglie wavelength of
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For an ideal gas, coefficient of volume expansion is given by
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Which of the following is not a green house gas?
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Two particles of masses $$m_1=m,m_2=2m$$ and charges $$q_1=q,q_2=2q$$ entered into uniform magnetic field. Find $$F_1/F_
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Work done in moving a charge of 25C is 50 J. Calculate potential difference, between two points.
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The correct arrangement in increasing order of wavelength of X-rays, UV rays, microwave is
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What is the electric field near infinite plane sheet of charge density $$\sigma$$ ?
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Which of the following waves are used to treatment of muscles ache?
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Find the logic gate, when both the inputs are high but the output is low and vice-versa.
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What is the minimum band-gap of the LED diode?
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The displacement of a wave is given by $$y = 20\cos (\omega t + 4z)$$ The amplitude of the given wave is
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If frequencies are $$(\nu-1)$$ and $$(\nu+2)$$, then find the value of beats.
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The function $$y = \log \omega t$$ can represent
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Two spring of force constant $$k_1$$ and $$k_2$$ are configured as the figure given below The angular frequency of this
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The resistance of a wire is R ohm. If it is melted and stretched to n times its original length, its new resistance will
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An unpolarised beam of intensity I$$_0$$ is incident on a pair of nicols making an angle of 60$$^\circ$$ with each other
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The collision of the molecules of an ideal gas is taken as
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The average energy associated with a monoatomic molecule is
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For the given electrical arrangement, what is the value of current I?
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If an electron in hydrogen atom jumps from an orbit of level $$n=3$$ to an orbit at level $$n=2$$, emitted radiation has
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Within the elastic limit, the corresponding stress is known as
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A wire is stretched to double of its length. The strain is
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Kepler's second law of planetary motion corresponds to
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A constant potential energy of a satellite is given as $$\mathrm{PE}=r(\mathrm{KE})$$ whee, PE = potential energy and KE
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A long solenoid has 20 turns cm$$^{-1}$$. The current necessary to produce a magnetic field of 20 mT inside the solenoid
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A constant current flows from A to B as shown in the figure. What is the direction of current in the circle?
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According to Pascal's law, pressure in a fluid at rest is the same at all points, if
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The surface tension of a liquid at its boiling point
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Centre of mass of the given system of particles will be at
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Newton's second law of rotational motion of a system particles having angular momentum L is given by
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The motion of a particle of mass $$m$$ is described by $$y = ut + g{t^2}$$. The force acting on the particle will be
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When a car of mass $$m$$ is moving with speed $$v$$ along a circle of radius $$r$$ on a level road, the centripetal forc
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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
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When the speed of light becomes $$\frac{2}{3}$$ of its present value, then the energy released in a given atomic explosi
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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
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The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and
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Two masses of 1g and 9g are moving with equal kinetic energy. The ratio of magnitude of their momentum is
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When two bodies collide with each other such that their kinetic energy remains constant. Their collision is said to be
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In detector, output circuit consists of $$R=10~k\Omega$$ and $$C=100~pF$$. The frequency of carrier signal which it can
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For motion under central forces, which quantity will be conserved?
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Which of the following statement is incorrect?
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If impedance is $$\sqrt3$$ times of resistance, then find phase difference.
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A bar magnet is oscillating in the earth's magnetic field with a period T. What happens to its period and motion, if its
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The relative permeability of iron is 6000. Its magnetic susceptibility is
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Which of the following technique is not used for measuring small time intervals?
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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
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In Young's double slit experiment with sodium vapour lamp of wavelength 589 nm and slit 0.589 mm apart, the half angular
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From the figure describing photoelectric effect, we may infer correctly that
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Carnot cycle of an engine is given below Total work done by the gas in one cycle is
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An optical fibre communication system works on a wavelength of 1.3 $$\mu$$m. The number of subscribers it can feed, if a
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