Resistance of the wire is measured as 2 and 3 at 10C and 30C respectively. Temperature co-efficient of resistance of the material of the wire 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.
Resistance of the wire is measured as 2 and 3 at 10C and 30C respectively. Temperature co-efficient of resistance of the material of the wire is :
A m long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If Ef and Fw are the reaction forces of the floor and the wall, then ratio of will be :
(Use g = 10 m/s2.)
An EM wave propagating in x-direction has a wavelength of 8 mm. The electric field vibrating y-direction has maximum magnitude of 60 Vm1. Choose the correct equations for electric and magnetic fields if the EM wave is propagating in vacuum :
In Young's double slit experiment performed using a monochromatic light of wavelength , when a glass plate ( = 1.5) of thickness x is introduced in the path of the one of the interfering beams, the intensity at the position where the central maximum occurred previously remains unchanged. The value of x will be :
In a Young's double slit experiment, an angular width of the fringe is 0.35 on a screen placed at 2 m away for particular wavelength of 450 nm. The angular width of the fringe, when whole system is immersed in a medium of refractive index 7/5, is . The value of is ___________.
A uniform disc with mass M = 4 kg and radius R = 10 cm is mounted on a fixed horizontal axle as shown in figure. A block with mass m = 2 kg hangs from a massless cord that is wrapped around the rim of the disc. During the fall of the block, the cord does not slip and there is no friction at the axle. The tension in the cord is ____________ N.
(Take g = 10 ms2)
Following statements related to radioactivity are given below :
(A) Radioactivity is a random and spontaneous process and is dependent on physical and chemical conditions.
(B) The number of un-decayed nuclei in the radioactive sample decays exponentially with time.
(C) Slope of the graph of loge (no. of undecayed nuclei) Vs. time represents the reciprocal of mean life time ().
(D) Product of decay constant () and half-life time (T1/2) is not constant.
Choose the most appropriate answer from the options given below :
What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and oxygen molecule dissociates into atomic oxygen?
Two point charges A and B of magnitude +8 106 C and 8 106 C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is 6.4 104 NC1. The distance 'd' between the point charges A and B is :
A water drop of radius 1 m falls in a situation where the effect of buoyant force is negligible. Co-efficient of viscosity of air is 1.8 105 Nsm2 and its density is negligible as compared to that of water 106 gm3. Terminal velocity of the water drop is :
(Take acceleration due to gravity = 10 ms2)
In the given circuit the input voltage Vin is shown in figure. The cut-in voltage of p-n junction diode (D1 or D2) is 0.6 V. Which of the following output voltage (V0) waveform across the diode is correct?




Water falls from a 40 m high dam at the rate of 9 104 kg per hour. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of 100 W lamps, that can be lit, is :
(Take g = 10 ms2)
A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60 J of heat during CA. A work of 50 J is done on the gas during the part BC. The internal energy of the gas at A is 1560 J. The workdone by the gas during the part CA is :
Two parallel, long wires are kept 0.20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is 2 106 N, then the value of x is approximately :
The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to 1.2 105. What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid?
A zener of breakdown voltage Vz = 8 V and maximum zener current, IZM = 10 mA is subjectd to an input voltage Vi = 10 V with series resistance R = 100 . In the given circuit RL represents the variable load resistance. The ratio of maximum and minimum value of RL is _____________.
A liquid of density 750 kgm3 flows smoothly through a horizontal pipe that tapers in cross-sectional area from A1 = 1.2 102 m2 to A2 = . The pressure difference between the wide and narrow sections of the pipe is 4500 Pa. The rate of flow of liquid is ___________ 103 m3s1.
A student in the laboratory measures thickness of a wire using screw gauge. The readings are 1.22 mm, 1.23 mm, 1.19 mm and 1.20 mm. The percentage error is . The value of x is ____________.
A block of mass 2 kg moving on a horizontal surface with speed of 4 ms1 enters a rough surface ranging from x = 0.5 m to x = 1.5 m. The retarding force in this range of rough surface is related to distance by F = kx where k = 12 Nm1. The speed of the block as it just crosses the rough surface will be :
All resistances in figure are 1 each. The value of current 'I' is A. The value of a is _________.
A car covers AB distance with first one-third at velocity v1 ms1, second one-third at v2 ms1 and last one-third at v3 ms1. If v3 = 3v1, v2 = 2v1 and v1 = 11 ms1 then the average velocity of the car is _____________ ms1.
A coil is placed in a time varying magnetic field. If the number of turns in the coil were to be halved and the radius of wire doubled, the electrical power dissipated due to the current induced in the coil would be :
(Assume the coil to be short circuited.)
Two objects of equal masses placed at certain distance from each other attracts each other with a force of F. If one-third mass of one object is transferred to the other object, then the new force will be :
In the given circuit, the magnitude of VL and VC are twice that of VR. Given that f = 50 Hz, the inductance of the coil is mH. The value of K is ____________.
Amplitude modulated wave is represented by . The total bandwidth of the amplitude modulated wave is :
Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength 1 and 2, respectively are incident on a metallic surface. If 1 = 32 then :
Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as and respectively. Here m and n are constants. The relations for distance and time in two systems respectively are :
A tunning fork of frequency 340 Hz resonates in the fundamental mode with an air column of length 125 cm in a cylindrical tube closed at one end. When water is slowly poured in it, the minimum height of water required for observing resonance once again is ___________ cm.
(Velocity of sound in air is 340 ms1)
A capacitor C1 of capacitance 5 F is charged to a potential of 30 V using a battery. The battery is then removed and the charged capacitor is connected to an uncharged capacitor C2 of capacitance 10 F as shown in figure. When the switch is closed charge flows between the capacitors. At equilibrium, the charge on the capacitor C2 is __________ C.
A ball is spun with angular acceleration = 6t2 2t where t is in second and is in rads2. At t = 0, the ball has angular velocity of 10 rads1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is :
In the above reaction 'A' is




Given below are two statements, one is Assertion (A) and other is Reason (R).
Assertion (A) : Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason (R) : The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.
In the light of the above statements, choose the correct one from the options given below :
The major product of the following reaction contains ____________ bromine atom(s).
Among the given complexes, number of paramagnetic complexes is ____________.
A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ___________. (Nearest integer)
(Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)
The major product (P) of the given reaction is
(where, Me is CH3)




Correct statement about photo-chemical smog is :
In the metallurgical extraction of copper, following reaction is used :
FeO + SiO2 FeSiO3
FeO and FeSiO3 respectively are.
Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula of the compound is,
Given : Atomic masses of C, H and N are 12, 1 and 14 amu respectively.
The molar mass of the compound A is 162 g mol1.
Match List - I with List - II :
| List-I (Oxide) | List-II (Nature) | ||
|---|---|---|---|
| (A) | (I) | Amphoteric | |
| (B) | (II) | Basic | |
| (C) | (III) | Neutral | |
| (D) | (IV) | Acidic |
Choose the correct answer from the options given below :
When sugar 'X' is boiled with dilute H2SO4 in alcoholic solution, two isomers 'A' and 'B' are formed. 'A' on oxidation with HNO3 yields saccharic acid where as 'B' is laevorotatory. The compound 'X' is :
100 g of an ideal gas is kept in a cylinder of 416 L volume at 27C under 1.5 bar pressure. The molar mass of the gas is __________ g mol1. (Nearest integer)
(Given : R = 0.083 L bar K1 mol1)
Match List - I with List - II :
| List-I | List-II | ||
|---|---|---|---|
| (A) | negatively charged sol | (I) | |
| (B) | macromolecular colloid | (II) | CdS sol |
| (C) | positively charged sol | (III) | Starch |
| (D) | Cheese | (IV) | a gel |
Choose the correct answer from the options given below:
For the given reactions
Sn2+ + 2e Sn
Sn4+ + 4e Sn
the electrode potentials are ; V and V. The magnitude of standard electrode potential for i.e. is _____________ 102 V. (Nearest integer)
Hydrogen has three isotopes : protium (1H), deuterium (2H or D) and tritium (3H or T). They have nearly same chemical properties but different physical properties. They differ in :
Among the following, basic oxide is :
0.01 M KMnO4 solution was added to 20.0 mL of 0.05 M Mohr's salt solution through a burette. The initial reading of 50 mL burette is zero. The volume of KMnO4 solution left in the burette after the end point is _____________ mL. (nearest integer)
Isobutyraldehyde on reaction with formaldehyde and K2CO3 gives compound 'A'. Compound 'A' reacts with KCN and yields compound 'B', which on hydrolysis gives a stable compound 'C'. The compound 'C' is




(a) CoCl3.4NH3, (b) CoCl3.5NH3, (c) CoCl3.6NH3 and (d) CoCl(NO3)2.5NH3.
Number of complex(es) which will exist in cis-trans form is/are _______________.
The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of CO2 and 0.442 g of H2O. The percentage of oxygen composition in the organic compound is ______________. (nearest integer)
In the structure of SF4, the lone pair of electrons on S is in.
A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of required to make buffer is ___________.
Given :
For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, CH = 601.70 kJ mol1, the magnitude of change in internal energy for the reaction is __________ kJ. (Nearest integer)
(Given : R = 8.3 J K1 mol1)
Which of the following oxoacids of sulphur contains "S" in two different oxidation states?
Consider the following statements :
(A) The principal quantum number 'n' is a positive integer with values of 'n' = 1, 2, 3, ...
(B) The azimuthal quantum number 'l' for a given 'n' (principal quantum number) can have values as 'l' = 0, 1, 2, ...... n
(C) Magnetic orbital quantum number 'ml' for a particular 'l' (azimuthal quantum number) has (2l + 1) values.
(D) 1/2 are the two possible orientations of electron spin.
(E) For l = 5, there will be a total of 9 orbital
Which of the above statements are correct?
The drug tegamet is :




With respect to the following reaction, consider the given statements :

(A) o-Nitroaniline and p-nitroaniline are the predominant products.
(B) p-Nitroaniline and m-nitroaniline are the predominant products.
(C) HNO3 acts as an acid.
(D) H2SO4 acts as an acid.
Choose the correct option.
Among the given oxides of nitrogen ; N2O, N2O3, N2O4 and N2O5, the number of compound/(s) having N - N bond is :
2.5 g of protein containing only glycine (C2H5NO2) is dissolved in water to make 500 mL of solution. The osmotic pressure of this solution at 300 K is found to be 5.03 103 bar. The total number of glycine units present in the protein is ____________.
(Given : R = 0.083 L bar K1 mol1)
The correct IUPAC name of the following compound is :
Let R1 = {(a, b) N N : |a b| 13} and
R2 = {(a, b) N N : |a b| 13}. Then on N :
Let f : R R be a differentiable function such that and and
let for . Then is equal to :
Let S = {1, 2, 3, 4}. Then the number of elements in the set { f : S S S : f is onto and f (a, b) = f (b, a) a (a, b) S S } is ______________.
If , then the value of (a b) is equal to ___________.
If the system of linear equations
,
, where , , R has infinitely many solutions then the value
of | 9 + 3 + 5 | is equal to ____________.
The probability that a randomly chosen one-one function from the set {a, b, c, d} to the set {1, 2, 3, 4, 5} satisfies f(a) + 2f(b) f(c) = f(d) is :
If cot = 1 and sec = , where and , then the value of and the quadrant in which + lies, respectively are :
Let be a vector which is perpendicular to the vector . If , then the projection of the vector on the vector is :
If n arithmetic means are inserted between a and 100 such that the ratio of the first mean to the last mean is 1 : 7 and a + n = 33, then the value of n is :
Let and , where . If the area of the parallelogram whose adjacent sides are represented by the vectors and is , then the value of is equal to :
If vertex of a parabola is (2, 1) and the equation of its directrix is 4x 3y = 21, then the length of its latus rectum is :
Let f(x) be a quadratic polynomial such that f(2) + f(3) = 0. If one of the roots of f(x) = 0 is 1, then the sum of the roots of f(x) = 0 is equal to :
Let the image of the point P(1, 2, 3) in the line be Q. Let R (, , ) be a point that divides internally the line segment PQ in the ratio 1 : 3. Then the value of 22 ( + + ) is equal to __________.
Let the slope of the tangent to a curve y = f(x) at (x, y) be given by 2 . If the curve passes through the point , then the value of is equal to :
Let a > 0, b > 0. Let e and l respectively be the eccentricity and length of the latus rectum of the hyperbola . Let e' and l' respectively be the eccentricity and length of the latus rectum of its conjugate hyperbola. If and , then the value of is equal to :
Let x = x(y) be the solution of the differential equation
such that x(1) = 0. Then, x(e) is equal to :
Suppose a class has 7 students. The average marks of these students in the maths examination is 62, and their variance is 20. A student fails in the examination if he/she gets less than 50 marks, then in worst case, the number of students can fail is _________.
Let A = \left( {\matrix{ {1 + i} & 1 \cr { - i} & 0 \cr } } \right) where . Then, the number of elements in the set { n {1, 2, ......, 100} : An = A } is ____________.
The term independent of x in the expansion of
is :
If one of the diameters of the circle is a chord of the circle , then the value of r2 is equal to ____________.
Let f, g : R R be functions defined by
f(x) = \left\{ {\matrix{ {[x]} & , & {x < 0} \cr {|1 - x|} & , & {x \ge 0} \cr } } \right. and g(x) = \left\{ {\matrix{ {{e^x} - x} & , & {x < 0} \cr {{{(x - 1)}^2} - 1} & , & {x \ge 0} \cr } } \right. where [x] denote the greatest integer less than or equal to x. Then, the function fog is discontinuous at exactly :
The area of the bounded region enclosed by the curve
and the x-axis is :
Let for n = 1, 2, ......, 50, Sn be the sum of the infinite geometric progression whose first term is n2 and whose common ratio is . Then the value of
is equal to ___________.
Let f : R R be a continuous function satisfying f(x) + f(x + k) = n, for all x R where k > 0 and n is a positive integer. If and , then :
Let a triangle be bounded by the lines L1 : 2x + 5y = 10; L2 : 4x + 3y = 12 and the line L3, which passes through the point P(2, 3), intersects L2 at A and L1 at B. If the point P divides the line-segment AB, internally in the ratio 1 : 3, then the area of the triangle is equal to :
Let the plane ax + by + cz = d pass through (2, 3, 5) and is perpendicular to the planes
2x + y 5z = 10 and 3x + 5y 7z = 12. If a, b, c, d are integers d > 0 and gcd (|a|, |b|, |c|, d) = 1, then the value of a + 7b + c + 20d is equal to :
The number of ways to distribute 30 identical candies among four children C1, C2, C3 and C4 so that C2 receives at least 4 and at most 7 candies, C3 receives at least 2 and at most 6 candies, is equal to :
The maximum number of compound propositions, out of prs, prs, pqs, prs, prs, pqs, qrs, qrs, pqs that can be made simultaneously true by an assignment of the truth values to p, q, r and s, is equal to __________.
The value of
is equal to :
Sum of squares of modulus of all the complex numbers z satisfying is equal to ___________.