Previous Year Questions
77 questions — organised by subject with solutions and explanations.
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An unknown alcohol is treated with the "Lucas reagent" to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism: [Main 2013]
The rate of a reaction doubles when its temperature changes from 300 K to 310 K . Activation energy of such a reaction will be: and [Main 2013]
A solution of chloro phenylethane is toluene racemises slowly in the presence of a small amount of , due to the formation of : [Main 2013]
Given Based on the data given above, strongest oxidising agent will be: [Main 2013]
Which one of the following molecules is expected to exhibit diamagnetic behaviour?[Main 2013]
Experimentally it was found that a metal oxide has formula . Metal M , is present as and in its oxide. Fraction of the metal which exists as would be: [Main 2013]
Which of the following represents the correct order of increasing first ionization enthalpy for Ca, Ba, S, Se and Ar?[Main 2013]
Four successive members of the first row transition elements are listed below with atomic numbers. Which one of them is expected to have the highest value?[Main 2013]
The molarity of a solution obtained by mixing 750 mL of with 250 mL of 2(M)HCl will be: [Main 2013]
A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of . The empirical formula of the hydrocarbon is:[Main 2013]
For gaseous state, if most probable speed is denoated by , average speed by and mean square speed by C, then for a large number of molecules the ratios of these speeds are:[Main 2013]
Compound (A), , gives a white precipitate when warmed with alcoholic .Oxidation of (A)gives a acid (B), .(B) easily forms anhydride on heating. Identify the compound (A).[Main 2013]
Synthesis of each molecule of glucose in photosynthesis involves:[Main 2013]
Which of the following exists as covalent crystals in the solid state?[Main 2013]
Stability of the species and increases in the order of: [Main 2013]
Which of the following is the wrong statement?[Main 2013]
Which of the following arrangements does not represent the correct order of the property stated against it?[Main 2013]
How many litres of water must be added to 1 litre of an aqueous solution of HCl with a pH of 1 to create an aqueous solution with pH of 2 ?[Main 2013]
The order of stability of the following carbocations: is [Main 2013]
Consider the following reaction: The values of x, y and z in the reaction are, respectively:[Main 2013]
Energy of an electron is given by Wavelength of light required to excite an electron in an hydrogen atom from level n = 1 to n = 2 will be [Main 2013]
In which of the following pairs of molecules/ions, both the species are not likely to exist?[Main 2013]
A compound with molecular mass 180 is acylated with to get a compound with molecular mass 390. The number of amino groups present per molecule of the former compound is: [Main 2013]
A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0° C. As it does so, it absorbs 208 J of heat. The values of q and w for the pro
Which of the following complex species is not expected to exhibit optical isomerism?[Main 2013]
The gas leaked from a storage tank of the Union Carbide plant in Bhopal gas tragedy was:[Main 2013]
An organic compound A upon reacting with gives B. On heating B gives C. C in presence of KOH reacts with to give . A is[Main 2013]
The first ionization potential of Na is 5.1 eV . The value of electron gain enthalpy of will be: [Main 2013]
All the students of a class performed poorly in Mathematics. The teacher decided to give grace marks of 10 to each of the students. Which of the following statistical measures will not change even aft
Distance between two parallel planes 2x + y + 2z = 8 and 4x + 2y + 4z + 5 = 0 is[Main 2013]
If then is equal to[Main 2013]
If is adjacent of a matrix A and ,then α is equal to[Main 2013]
if the lines and are coplanar, then k can have[Main 2013]
If x, y, z are in A.P. and and are also in A.P., then[Main 2013]
The area (in square units) bounded by the curves ,x-axis,and lying in the first quadrant is[Main 2013]
If z is a complex number of unit modulus and argument θ, then equals[Main 2013]
The intercepts on x-axis made by tangents to the curve, which are parallel to the line , are equal to[Main 2013]
A multiple choice examination has 5 questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get 4 or more correct answers just by gu
The real number k for which the equation, has two distinct real roots in [Main 2013]
The number of values of , for which the system of equations: has no solution, is[Main 2013]
Let A and B be two sets containing 2 elements and 4 elements respectively. The number of subsets of A × B having 3 or more elements is[Main 2013]
If the equations and , a, b, c ∈ R, have a common root, then a : b : c is[Main 2013]
Let be the number of all a possible triangles formed by joining vertices of an n-sided regular polygon.If ,then the value of n is[Main 2013]
[Main 2013]
If ,then at x = 1 is equal to[Main 2013]
Statement − I : The value of the integral is equal to Statement II : [Main 2013]
This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements.Statement- I: Higher the range, greater is the res
An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M. The piston and cylinder have equal cross sectional area A. When the piston is in equilibrium, the v
If the vectors and are the sides of triangle ABC,then the length of the median through A is[Main 2013]
The graph between angle of deviation (δ) and angle of incidence (i) for a triangular prism is represented by[Main 2013]
A projectile is given an initial velocity of ,where is along the ground is along the vertical.If ,the equation of its trajectory is:[Main 2013]
Two coherent point sources S1S_1S1 and S2S_2S2 are separated by a small distance ‘d’ as shown. The fringes obtained on the screen will be: [Main 2013]
A hoop of radius r and mass m rotating with an angular velocity is placed on a rough horizontal surface. The initial velocity of the centre of the hoop is zero. What will be the velocity of the centre
The supply voltage to a room is 120 V. The resistance of the lead wires is 6 Ω. A 60 W bulb is already switched on. What is the decrease of voltage across the bulb, when a 240 W heater is switched on
In a hydrogen like atom electron makes transition from an energy level with quantum number n to another with quantum number (n – 1). If n >> 1, the frequency of radiation emitted is proportional to In
Two charges, each equal to q, are kept at and on the x-axis. A particle of mass m and charge is placed at the origin. If charge is given a small displacement (y a) along the y-axis, the net force ac
The I – V characteristic of an LED is[Main 2013]
A uniform cylinder of length L and mass M having cross-sectional area A is suspended, with its length vertical, from a fixed point by a massless spring, such that it is half submerged in a liquid of d
If a piece of metal is heated to temperature θ and then allowed to cool in a room which is at temperature the graph between the temperature T of the metal and time t will be closest to :[Main 2013]
The amplitude of a damped oscillator decreases to 0.9 times its original magnitude is 5s. In another 10s it will decrease to α times its original magnitude, where α equals.[Main 2013]
Two short bar magnets of length 1 cm each have magnetic moments and respectively.They are placed on a horizontal table parallel to each other with their N poles pointing towards the South.They have a
The magnetic field in a travelling electromagnetic wave has a peak value of 20 nT. The peak value of electric field strength is :[Main 2013]
A metallic rod of length is tied to a string of length and made to rotate with angular speed on a horizontal table with one end of the string fixed. If there is a vertical magnetic field ‘B’ in the re
A charge Q is uniformly distributed over a long rod AB of length L as shown in the figure. The electric potential at the point O lying at a distance L from the end A is: [Main 2013]
A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is 15
A beam of unpolarised light of intensity is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. T
A diode detector is used to detect an amplitude modulated wave of 60% modulation by using a condenser of capacity 250 pico farad in parallel with a load resistance 100 kilo ohm. Find the maximum modul
In an LCR circuit as shown below both switches are open initially. Now switch is closed, kept open. (q is charge on the capacitor and τ = RC is capacitive time constant). Which of the following statem
A sonometer wire of length 1.5 m is made of steel. The tension in it produces an elastic strain of 1 %. What is the fundamental frequency of steel if density and elasticity of steel are and respective
Two capacitors and are charged to 120 V and 200 V respectively. It is found that by connectingthem together the potential on each one can be made zero. Then :[Main 2013]
The anode voltage of a photocell is kept fixed. The wavelength of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows:[Main 2013]
Assume that a drop of liquid evaporates by decrease in its surface energy, so that its temperature remains unchanged. What should be the minimum radius of the drop for this to be possible? The surface
Let denote the dimensional formula of the permittivity of vacuum. If M = mass, L = length, T = time and A = electric current, then:[Main 2013]
Diameter of plano-convex lens is 6 cm and thickness at the centre is 3 mm. If speed of light in material of lens is , the focal length of the lens is :[Main 2013]
What is the minimum energy required to launch a satellite of mass m from the surface of a planet of mass M and radius R in a circular orbit at an altitude of 2R?[Main 2013]
The above p-v diagram represents the thermodynamic cycle of an engine, operating with an ideal monoatomic gas. The amount of heat extracted from the source in a single cycle is[Main 2013]
This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statements.Statement – I : A point particle of mass m moving