A spherical drop of liquid splits into 1000 identical spherical drops. If u is the surface energy of the original drop and u is the total surface energy of the resulting drops, the (ignoring evaporation), . Then value of x is ____________ :

Official solved question paper for Joint Entrance Examination (Main). Review all 90 questions, official answer keys, and detailed step-by-step solutions below, or attempt online with timer and negative marking.
A spherical drop of liquid splits into 1000 identical spherical drops. If u is the surface energy of the original drop and u is the total surface energy of the resulting drops, the (ignoring evaporation), . Then value of x is ____________ :
A particle executes simple harmonic motion between and . If time taken by particle to go from to is 2 s; then time taken by particle in going from to A is
Every planet revolves around the sun in an elliptical orbit :-
A. The force acting on a planet is inversely proportional to square of distance from sun.
B. Force acting on planet is inversely proportional to product of the masses of the planet and the sun.
C. The Centripetal force acting on the planet is directed away from the sun.
D. The square of time period of revolution of planet around sun is directly proportional to cube of semi-major axis of elliptical orbit.
Choose the correct answer from the options given below :
If a solid sphere of mass 5 kg and a disc of mass 4 kg have the same radius. Then the ratio of moment of inertia of the disc about a tangent in its plane to the moment of inertia of the sphere about its tangent will be . The value of is ___________.
An object is placed on the principal axis of convex lens of focal length 10cm as shown. A plane mirror is placed on the other side of lens at a distance of 20 cm. The image produced by the plane mirror is 5cm inside the mirror. The distance of the object from the lens is ___________ cm.

Two objects are projected with same velocity 'u' however at different angles and with the horizontal. If , the ratio of horizontal range of the first object to the 2nd object will be :
A capacitor has capacitance 5F when it's parallel plates are separated by air medium of thickness d. A slab of material of dielectric constant 1.5 having area equal to that of plates but thickness is inserted between the plates. Capacitance of the capacitor in the presence of slab will be __________ F.
The energy levels of an atom is shown in figure.

Which one of these transitions will result in the emission of a photon of wavelength 124.1 nm?
Given (h = 6.62 10 Js)
Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3. Cell 2 has emf of 6V and internal resistance of 6. An external resistor R of 4 is connected across A and B. The current flowing through R will be ____________ A.

According to law of equipartition of energy the molar specific heat of a diatomic gas at constant volume where the molecule has one additional vibrational mode is :-
A nucleus disintegrates into two smaller parts, which have their velocities in the ratio 3 : 2. The ratio of their nuclear sizes will be . The value of '' is :-
Match List I with List II
| List I | List II | ||
|---|---|---|---|
| A. | Gauss's Law in Electrostatics | I. | |
| B. | Faraday's Law | II. | |
| C. | Gauss's Law in Magnetism | III. | |
| D. | Ampere-Maxwell Law | IV. |
Choose the correct answer from the options given below :
For a moving coil galvanometer, the deflection in the coil is 0.05 rad when a current of 10 mA is passes through it. If the torsional constant of suspension wire is , the magnetic field is 0.01T and the number of turns in the coil is 200, the area of each turn (in cm) is :
A point charge of 10 C is placed at the origin. At what location on the X-axis should a point charge of 40 C be placed so that the net electric field is zero at cm on the X-axis?
Two long parallel wires carrying currents 8A and 15A in opposite directions are placed at a distance of 7 cm from each other. A point P is at equidistant from both the wires such that the lines joining the point P to the wires are perpendicular to each other. The magnitude of magnetic field at P is _____________ T.
(Given : )
Given below are two statements :
Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below
A series LCR circuit is connected to an AC source of 220 V, 50 Hz. The circuit contains a resistance R = 80, an inductor of inductive reactance , and a capacitor of capacitive reactance . The power factor of circuit is . The value of is :
Consider a block kept on an inclined plane (incline at 45) as shown in the figure. If the force required to just push it up the incline is 2 times the force required to just prevent it from sliding down, the coefficient of friction between the block and inclined plane() is equal to :

The distance travelled by a particle is related to time t as . The velocity of the particle at t=5s is :-
The graph between two temperature scales P and Q is shown in the figure. Between upper fixed point and lower fixed point there are 150 equal divisions of scale P and 100 divisions on scale Q. The relationship for conversion between the two scales is given by :-

A train blowing a whistle of frequency 320 Hz approaches an observer standing on the platform at a speed of 66 m/s. The frequency observed by the observer will be (given speed of sound = 330 ms) __________ Hz.
A body of mass 1 kg collides head on elastically with a stationary body of mass 3 kg. After collision, the smaller body reverses its direction of motion and moves with a speed of 2 m/s. The initial speed of the smaller body before collision is ___________ ms.
The resistance of a wire is 5 . It's new resistance in ohm if stretched to 5 times of it's original length will be :
Match List I with List II
| List I | List II | ||
|---|---|---|---|
| A. | Troposphere | I. | Approximate 65-75 km over Earth's surface |
| B. | E-Part of Stratosphere | II. | Approximate 300 km over Earth's surface |
| C. | F-Part of Thermosphere | III. | Approximate 10 km over Earth's surface |
| D. | D-Part of Stratosphere | IV. | Approximate 100 km over Earth's surface |
Choose the correct answer from the options given below :
A wire of length 1m moving with velocity 8 m/s at right angles to a magnetic field of 2T. The magnitude of induced emf, between the ends of wire will be __________.
A body of mass is taken from earth surface to the height h equal to twice the radius of earth (R), the increase in potential energy will be :
(g = acceleration due to gravity on the surface of Earth)
Statement I : When a Si sample is doped with Boron, it becomes P type and when doped by Arsenic it becomes N-type semi conductor such that P-type has excess holes and N-type has excess electrons.
Statement II : When such P-type and N-type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ameter.
In the light of above statements, choose the most appropriate answer from the options given below
The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are :-
A. Real
B. Erect
C. Smaller in size then object
D. Laterally inverted
Choose the most appropriate answer from the options given below :
Match List I with List II
| List I | List II | ||
|---|---|---|---|
| A. | Young's Modulus (Y) | I. | |
| B. | Co-efficient of Viscosity () | II. | |
| C. | Planck's Constant (h) | III. | |
| D. | Work function () | IV. |
Choose the correct answer from the options given below :
Match List I with List II
| List I | List II | ||
|---|---|---|---|
| A. | Isothermal Process | I. | Work done by the gas decreases internal energy |
| B. | Adiabatic Process | II. | No change in internal energy |
| C. | Isochoric Process | III. | The heat absorbed goes partly to increase internal energy and partly to do work |
| D. | Isobaric Process | IV. | No work is done on or by the gas |
Choose the correct answer from the options given below :
A first order reaction has the rate constant, . The number of correct statement/s from the following is/are __________
Given :
A. Reaction completes in 1000 s.
B. The reaction has a half-life of 500 s.
C. The time required for 10% completion is 25 times the time required for 90% completion.
D. The degree of dissociation is equal to ()
E. The rate and the rate constant have the same unit.
The number of pairs of the solutions having the same value of the osmotic pressure from the following is _________.
(Assume 100% ionization)
A. 0.500 and 0.25
B. 0.100 and 0.100
C. 0.05 and 0.25
D. 0.15 and 0.1
E. 0.02 and 0.05
The isomeric deuterated bromide with molecular formula having two chiral carbon atoms is
Which one among the following metals is the weakest reducing agent?
Based on the given figure, the number of correct statement/s is/are __________.

A. Surface tension is the outcome of equal attractive and repulsive forces acting on the liquid molecule in bulk.
B. Surface tension is due to uneven forces acting on the molecules present on the surface.
C. The molecule in the bulk can never come to the liquid surface.
D. The molecules on the surface are responsible for vapour pressure if the system is a closed system.
A. Ammonium salts produce haze in atmosphere.
B. Ozone gets produced when atmospheric oxygen reacts with chlorine radicals.
C. Polychlorinated biphenyls act as cleansing solvents.
D. 'Blue baby' syndrome occurs due to the presence of excess of sulphate ions in water.
Choose the correct answer from the options given below :
Match List I with List II
| List I Coordination entity |
List II Wavelength of light absorbed in nm |
||
|---|---|---|---|
| A. | I. | 310 | |
| B. | II. | 475 | |
| C. | III. | 535 | |
| D. | IV. | 600 |
Choose the correct answer from the options given below :
Potassium dichromate acts as a strong oxidizing agent in acidic solution. During this process, the oxidation state changes from :
Given below are two statements :
Statement I : In froth floatation method of rotating paddle agitates the mixture to drive air out of it.
Statement II : Iron pyrites and generally avoided for extraction of iron due to environmental reasons.
In the light of the above statements, choose the correct answer from the options given below :
28.0 L of CO is produced on complete combustion of 16.8 L gaseous mixture of ethene and methane at 25C and 1 atm. Heat evolved during the combustion process is ___________ kJ.
Given :
Which of the following represents the correct order of metallic character of the given elements?
Match List I with List II
| List I | List II | ||
|---|---|---|---|
| A. | Cobalt catalyst | I. | production |
| B. | Syngas | II. | Water gas production |
| C. | Nickel catalyst | III. | Coal gasification |
| D. | Brine solution | IV. | Methanol production |
Choose the correct answer from the options given below :
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Carbon forms two important oxides - CO and CO. CO is neutral whereas CO is acidic in nature
Reason R : CO can combine with water in a limited way to form carbonic acid, while CO is sparingly soluble in water
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : The alkali metals and their salts impart characteristic colour to reducing flame.
Reason R : Alkali metals can be detected using flame tests.
In the light of the above statements, choose the most appropriate answer from the options given below :
Match List I with List II
| List I (Name of polymer) | List II (Uses) | ||
|---|---|---|---|
| A. | Glyptal | I. | Flexible pipes |
| B. | Neoprene | II. | Synthetic wool |
| C. | Acrilan | III. | Paints and Lacquers |
| D. | LDP | IV. | Gaskets |
Choose the correct answer from the options given below :
When the hydrogen ion concentration [H] changes by a factor of 1000, the value of pH of the solution __________
Match List I with List II
| List I (Amines) | List II () | ||
|---|---|---|---|
| A. | Aniline | I. | 3.25 |
| B. | Ethanamine | II. | 3.00 |
| C. | N-Ethylethanamine | III. | 9.38 |
| D. | N, N-Diethylethanamine | IV. | 3.29 |
Choose the correct answer from the options given below :
Match List I with List II
| List I Isomeric pairs |
List II Type of isomers |
||
|---|---|---|---|
| A. | Propanamine and N-Methylethanamine | I. | Metamers |
| B. | Hexan-2-one and Hexan-3-one | II. | Positional isomers |
| C. | Ethanamide and Hydroxyethanimine | III. | Functional isomers |
| D. | o-nitrophenol and p-nitrophenol | IV. | Tautomers |
Choose the correct answer from the options given below :
A chloride salt solution acidified with dil.HNO gives a curdy white precipitate, [A], on addition of AgNO. [A] on treatment with NHOH gives a clear solution B. A and B are respectively :
Find out the major product from the following reaction.





Statement I : Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the negative centre and head pointing towards the positive centre.
Statement II : The crossed arrow of the dipole moment symbolizes the direction of the shift of charges in the molecules.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Butylated hydroxy anisole when added to butter increases its shelf life.
Reason R : Butylated hydroxy anisole is more reactive towards oxygen than food.
In the light of the above statements, choose the most appropriate answer from the options given below
What is the mass ratio of ethylene glycol (, molar mass = 62 g/mol) required for making 500 g of 0.25 molal aqueous solution and 250 mL of 0.25 molar aqueous solution?
The for the given cell is 0.1115 V at 298 K when
The value of is ____________
Given : V
'A' in the given reaction is





Total number of moles of AgCl precipitated on addition of excess of AgNO to one mole each of the following complexes and is ___________.
Number of hydrogen atoms per molecule of a hydrocarbon A having 85.8% carbon is __________
(Given : Molar mass of A = 84 g mol)
The number of given orbitals which have electron density along the axis is _________
Number of compounds giving (i) red colouration with ceric ammonium nitrate and also (ii) positive iodoform test from the following is ___________

The number of incorrect statement/s from the following is/are ___________
A. Water vapours are adsorbed by anhydrous calcium chloride.
B. There is a decrease in surface energy during adsorption.
C. As the adsorption proceeds, H becomes more and more negative.
D. Adsorption is accompanied by decrease in entropy of the system.
Let and . Then is equal to :
Let A = \left[ {\matrix{ {{1 \over {\sqrt {10} }}} & {{3 \over {\sqrt {10} }}} \cr {{{ - 3} \over {\sqrt {10} }}} & {{1 \over {\sqrt {10} }}} \cr } } \right] and B = \left[ {\matrix{ 1 & { - i} \cr 0 & 1 \cr } } \right], where . If , then the inverse of the matrix is
Let , and . Then the sum of all the positive integer divisors of is
The integral is equal to
For the two positive numbers if and are in a geometric progression, while and are in an arithmetic progression, then is equal to _________.
If the four points, whose position vectors are and are coplanar, then is equal to :
The number of numbers, strictly between 5000 and 10000 can be formed using the digits 1, 3, 5, 7, 9 without repetition, is :
Points P(3, 2), Q(9, 10) and R() lie on a circle C and PR as its diameter. The tangents to C at the points Q and R intersect at the point S. If S lies on the line , then k is equal to ____________.
25% of the population are smokers. A smoker has 27 times more chances to develop lung cancer than a non smoker. A person is diagnosed with lung cancer and the probability that this person is a smoker is . Then the value of k is __________.
If the shortest distance between the line joining the points (1, 2, 3) and (2, 3, 4), and the line is , then 28 is equal to ____________.
Let A, B, C be 3 3 matrices such that A is symmetric and B and C are skew-symmetric. Consider the statements
(S1) A B B A is symmetric
(S2) A C C A is symmetric
Then,
Let N be the sum of the numbers appeared when two fair dice are rolled and let the probability that are in geometric progression be . Then the value of k is :
Let and let be the roots of the equation . If , then the product of all possible values of is ____________.
The number of functions
satisfying is
The remainder when (2023) is divided by 35 is __________.
Suppose Anil's mother wants to give 5 whole fruits to Anil from a basket of 7 red apples, 5 white apples and 8 oranges. If in the selected 5 fruits, at least 2 oranges, at least one red apple and at least one white apple must be given, then the number of ways, Anil's mother can offer 5 fruits to Anil is ____________
Let the function have a maxima for some value of and a minima for some value of . Then, the set of all values of p is
is equal to :
Let T and C respectively be the transverse and conjugate axes of the hyperbola . Then the area of the region above the parabola , below the transverse axis T and on the right of the conjugate axis C is :
Let be such that is a tautology. Then
If the function f(x) = \left\{ {\matrix{ {(1 + |\cos x|)^{\lambda \over {|\cos x|}}} & , & {0 < x < {\pi \over 2}} \cr \mu & , & {x = {\pi \over 2}} \cr e^{{{\cot 6x} \over {{}\cot 4x}}} & , & {{\pi \over 2} < x < \pi } \cr } } \right.
is continuous at , then is equal to
The foot of perpendicular of the point (2, 0, 5) on the line is (). Then, which of the following is NOT correct?
A triangle is formed by X-axis, Y-axis and the line . Then the number of points P(a, b) which lie strictly inside the triangle, where a is an integer and b is a multiple of a, is ____________.
Let be a complex number such that . Then lies on the circle of radius 2 and centre :
Let be a function defined by , for some , such that the range of is [0, 2]. Then the value of is _________
If , where m and n are coprime natural numbers, then is equal to _____________.
Let be a solution of the differential equation where, and . Then
The equations of two sides of a variable triangle are and , and its third side is a tangent to the parabola . The locus of its circumcentre is :
The shortest distance between the lines and is :
If m and n respectively are the numbers of positive and negative values of in the interval that satisfy the equation , then mn is equal to ____________.