If a wave gets refracted into a denser medium, then which of the following is true?

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.
If a wave gets refracted into a denser medium, then which of the following is true?
For a perfect gas, two pressures P1 and P2 are shown in figure. The graph shows :
A lead bullet penetrates into a solid object and melts. Assuming that 40% of its kinetic energy is used to heat it, the initial speed of bullet is :
(Given : initial temperature of the bullet = 127C, Melting point of the bullet = 327C, Latent heat of fusion of lead = 2.5 104 J kg1, Specific heat capacity of lead = 125 J/kg K)
The cut-off voltage of the diodes (shown in figure) in forward bias is 0.6 V. The current through the resister of 40 is __________ mA.
If L, C and R are the self inductance, capacitance and resistance respectively, which of the following does not have the dimension of time?
One end of a massless spring of spring constant k and natural length l0 is fixed while the other end is connected to a small object of mass m lying on a frictionless table. The spring remains horizontal on the table. If the object is made to rotate at an angular velocity about an axis passing through fixed end, then the elongation of the spring will be :
The SI unit of a physical quantity is pascal-second. The dimensional formula of this quantity will be :
Two long parallel conductors S1 and S2 are separated by a distance 10 cm and carrying currents of 4A and 2A respectively. The conductors are placed along x-axis in X-Y plane. There is a point P located between the conductors (as shown in figure).
A charge particle of 3 coulomb is passing through the point P with velocity m/s; where and represents unit vector along x & y axis respectively.
The force acting on the charge particle is N. The value of x is :
A diatomic gas ( = 1.4) does 400J of work when it is expanded isobarically. The heat given to the gas in the process is __________ J.
A mass of 10 kg is suspended vertically by a rope of length 5 m from the roof. A force of 30 N is applied at the middle point of rope in horizontal direction. The angle made by upper half of the rope with vertical is = tan1 (x 101). The value of x is ____________.
(Given, g = 10 m/s2)
The current density in a cylindrical wire of radius r = 4.0 mm is 1.0 106 A/m2. The current through the outer portion of the wire between radial distances and r is x A; where x is __________.
The equation of a particle executing simple harmonic motion is given by . At t = 1s, the speed of particle will be
(Given : = 3.14)
A parallel plate capacitor is made up of stair like structure with a plate area A of each stair and that is connected with a wire of length b, as shown in the figure. The capacitance of the arrangement is . The value of x is ____________.
When a ball is dropped into a lake from a height 4.9 m above the water level, it hits the water with a velocity v and then sinks to the bottom with the constant velocity v. It reaches the bottom of the lake 4.0 s after it is dropped. The approximate depth of the lake is :
According to kinetic theory of gases,
A. The motion of the gas molecules freezes at 0C.
B. The mean free path of gas molecules decreases if the density of molecules is increased.
C. The mean free path of gas molecules increases if temperature is increased keeping pressure constant.
D. Average kinetic energy per molecule per degree of freedom is (for monoatomic gases).
Choose the most appropriate answer from the options given below :
A deuteron and a proton moving with equal kinetic energy enter into a uniform magnetic field at right angle to the field. If rd and rp are the radii of their circular paths respectively, then the ratio will be : 1 where x is __________.
In the given circuit 'a' is an arbitrary constant. The value of m for which the equivalent circuit resistance is minimum, will be . The value of x is __________.
The distance of the Sun from earth is 1.5 1011 m and its angular diameter is (2000) s when observed from the earth. The diameter of the Sun will be :
A convex lens has power P. It is cut into two halves along its principal axis. Further one piece (out of the two halves) is cut into two halves perpendicular to the principal axis (as shown in figures). Choose the incorrect option for the reported pieces.
We do not transmit low frequency signal to long distances because-
(a) The size of the antenna should be comparable to signal wavelength which is unreal solution for a signal of longer wavelength.
(b) Effective power radiated by a long wavelength baseband signal would be high.
(c) We want to avoid mixing up signals transmitted by different transmitter simultaneously.
(d) Low frequency signal can be sent to long distances by superimposing with a high frequency wave as well.
Therefore, the most suitable option will be :
If a charge q is placed at the centre of a closed hemispherical non-conducting surface, the total flux passing through the flat surface would be :
A stone tide to a spring of length L is whirled in a vertical circle with the other end of the spring at the centre. At a certain instant of time, the stone is at its lowest position and has a speed u. The magnitude of change in its velocity, as it reaches a position where the string is horizontal, is . The value of x is -
A rolling wheel of 12 kg is on an inclined plane at position P and connected to a mass of 3 kg through a string of fixed length and pulley as shown in figure. Consider PR as friction free surface. The velocity of centre of mass of the wheel when it reaches at the bottom Q of the inclined plane PQ will be m/s. The value of x is ___________.
A particle executes simple harmonic motion. Its amplitude is 8 cm and time period is 6 s. The time it will take to travel from its position of maximum displacement to the point corresponding to half of its amplitude, is ___________ s.
Given below are two statements :
Statement I : In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit (E1) to higher energy orbit (E2), is given as hf = E1 E2
Statement II : The jumping of electron from higher energy orbit (E2) to lower energy orbit (E1) is associated with frequency of radiation given as f = (E2 E1)/h
This condition is Bohr's frequency condition.
In the light of the above statements, choose the correct answer from the options given below :
For a transistor to act as a switch, it must be operated in
A metallic rod of length 20 cm is placed in North-South direction and is moved at a constant speed of 20 m/s towards East. The horizontal component of the Earth's magnetic field at that place is 4 103 T and the angle of dip is 45. The emf induced in the rod is ___________ mV.
Given below are two statements :
Statement I : A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.
Statement II : In a material medium, the EM wave travels with speed . In the light of the above statements, choose the correct answer from the options given below.
Three identical charged balls each of charge 2 C are suspended from a common point P by silk threads of 2 m each (as shown in figure). They form an equilateral triangle of side 1m.
The ratio of net force on a charged ball to the force between any two charged balls will be :
Four spheres each of mass m from a square of side d (as shown in figure). A fifth sphere of mass M is situated at the centre of square. The total gravitational potential energy of the system is :
116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of oxygen and 48.5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following?
A. CH3COOH, B. HCHO, C. CH3OOCH3, D. CH3CHO
For the reaction taking place in the cell :
Pt (s)| H2 (g)|H+(aq) || Ag+(aq) |Ag (s)
E = + 0.5332 V.
The value of fG is ______________ kJ mol1. (in nearest integer)
On the surface of polar stratospheric clouds, hydrolysis of chlorine nitrite gives A and B while its reaction with its reaction with HCl produces B and C. A, B and C are, respectively :
Consider the following set of quantum numbers.
| n | 1 | m | |
|---|---|---|---|
| A. | 3 | 3 | 3 |
| B. | 3 | 2 | 2 |
| C. | 2 | 1 | +1 |
| D. | 2 | 2 | +2 |
The number of correct sets of quantum numbers is __________.
Which amongst the given plots is the correct plot for pressure (p) vs density (d) for an ideal gas?




Product 'A' of following sequence of reactions is





Which is true about Buna-N?
Given below are two statements.
Statement I : Maltose has two -D-glucose units linked at C1 and C4 and is a reducing sugar.
Statement II : Maltose has two monosaccharides : -D-glucose and -D-glucose linked at C1 and C6 and it is a non-reducing sugar.
In the light of the above statements, choose the correct answer from the options given below :
pH value of 0.001 M NaOH solution is ____________.
The gas produced by treating an aqueous solution of ammonium chloride with sodium nitrite is :
Match List I with List II.
| List-I (Anion) |
List-II (gas evolved on reaction with dil.HSO) |
||
|---|---|---|---|
| (A) | CO | I. | Colourless gas which turns lead acetate paper black. |
| (B) | S | II. | Colourless gas which turns acidified potassium dichromate solution green. |
| (C) | SO | III. | Brown fumes which turns acidified KI solution containing starch blue. |
| (D) | NO | IV. | Colourless gas evolved with brisk effervescence, which turns lime water milky. |
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 : Fluorine forms one oxoacid.
Reason R : Fluorine has smallest size amongst all halogens and is highly electronegative.
In the light of the above statements, choose the most appropriate answer from the options given below :
A solution containing 2.5 103 kg of a solute dissolved in 75 103 kg of water boils at 373.535 K. The molar mass of the solute is ____________ g mol1. [nearest integer] (Given : Kb(H2O) = 0.52 K kg mol1 and boiling point of water = 373.15 K)
Match List-I with List-II.
| List-I | List-II | ||
|---|---|---|---|
| (A) | ![]() |
I. | in |
| (B) | |
II. | |
| (C) | |
III. | |
| (D) | |
IV. |
Choose the correct answer from the options given below :
[Given : Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]
Identify the incorrect statement for PCl5 from the following.
Decarboxylation of all six possible forms of diaminobenzoic acids C6H3(NH2)2COOH yields three products A, B and C. Three acids give a product 'A', two acids gives a product 'B' and one acid give a product 'C'. The melting point of product 'C' is
Arrange the following coordination compounds in the increasing order of magnetic moments. (Atomic numbers : Mn = 25; Fe = 26)
A. [FeF6]3
B. [Fe(CN)6]3
C. [MnCl6]3 (high spin)
D. [Mn(CN)6]3
Choose the correct answer from the options given below :
The correct order of increasing ionic radii is
What will be the major product of following sequence of reactions?





Which of the following is most stable?





If the initial pressure of a gas is 0.03 atm, the mass of the gas adsorbed per gram of the adsorbent is ___________ 102 g.
0.25 g of an organic compound containing chlorine gave 0.40 g of silver chloride in Carius estimation. The percentage of chlorine present in the compound is ___________. [in nearest integer]
(Given : Molar mass of Ag is 108 g mol1 and that of Cl is 35.5 g mol1)
Statement I : Leaching of gold with cyanide ion in absence of air / O2 leads to cyano complex of Au(III).
Statement II : Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements, choose the correct answer from the options given below.
When 5 moles of He gas expand isothermally and reversibly at 300 K from 10 litre to 20 litre, the magnitude of the maximum work obtained is __________ J. [nearest integer] (Given : R = 8.3 J K1 mol1 and log 2 = 0.3010)
BeO reacts with HF in presence of ammonia to give [A] which on thermal decomposition produces [B] and ammonium fluoride. Oxidation state of Be in [A] is ____________.
In 3d series, the metal having the highest M2+/M standard electrode potential is :
Match List-I with List-II
| List-I | List-II | ||
|---|---|---|---|
| (A) | Antipyretic | I. | Reduces pain |
| (B) | Analgesic | II. | Reduces stress |
| (C) | Tranquilizer | III. | Reduces fever |
| (D) | Antacid | IV. | Reduces acidity (stomach) |
Choose the correct answer from the options given below :
The correct order of increasing intermolecular hydrogen bond strength is
It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be ____________ kJ mol1. [nearest integer]
(Given ln10 = 2.3, R = 8.3 J K1 mol1, log 2 = 0.30)
Let f(x) = \left| {\matrix{ a & { - 1} & 0 \cr {ax} & a & { - 1} \cr {a{x^2}} & {ax} & a \cr } } \right|,\,a \in R. Then the sum of the squares of all the values of a, for which , is
Let S = {E1, E2, ........., E8} be a sample space of a random experiment such that for every n = 1, 2, ........, 8. Then the number of elements in the set is ___________.
The value of is :
The mean and variance of the data 4, 5, 6, 6, 7, 8, x, y, where x < y, are 6 and respectively. Then is equal to :
Let A and B be two 3 3 matrices such that and . Then is equal to
The shortest distance between the lines
and , is :
Which of the following statement is a tautology?
Let . Then 4S is equal to
Let be the solution of the differential equation , and . If , then k1 is equal to _____________.
The integral , where [ . ] denotes the greatest integer function, is equal to
If a point A(x, y) lies in the region bounded by the y-axis, straight lines 2y + x = 6 and 5x 6y = 30, then the probability that y < 1 is :
If m and n respectively are the number of local maximum and local minimum points of the function , then the ordered pair (m, n) is equal to
The set of values of k, for which the circle lies inside the fourth quadrant and the point lies on or inside the circle C, is :
Let f be a differentiable function in . If , then is equal to
If a1, a2, a3 ...... and b1, b2, b3 ....... are A.P., and a1 = 2, a10 = 3, a1b1 = 1 = a10b10, then a4 b4 is equal to -
If the equation of the parabola, whose vertex is at (5, 4) and the directrix is , is , then is equal to :
Let [t] denote the greatest integer t and {t} denote the fractional part of t. The integral value of for which the left hand limit of the function
at x = 0 is equal to , is _____________.
Let and be the vectors along the diagonals of a parallelogram having area . Let the angle between and be acute, , and . If , then an angle between and is :
If , then at x = 1 is equal to ____________.
Let for some real numbers and , . If the system of equations and has more than one solution, then is equal to
If the area of the region is A, then is equal to __________.
The number of points of intersection of
and , z C, is :
is a root of which of the following equation?
Let S = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}. Define f : S S as
f(n) = \left\{ {\matrix{ {2n} & , & {if\,n = 1,2,3,4,5} \cr {2n - 11} & , & {if\,n = 6,7,8,9,10} \cr } } \right..
Let g : S S be a function such that fog(n) = \left\{ {\matrix{ {n + 1} & , & {if\,n\,\,is\,odd} \cr {n - 1} & , & {if\,n\,\,is\,even} \cr } } \right..
Then is equal to _____________.
If the solution curve of the differential equation
passes through the point (1, 0), then the abscissa of the point on the curve whose ordinate is tan(1), is
Let the foot of the perpendicular from the point (1, 2, 4) on the line be P. Then the distance of P from the plane is :
Let A be a matrix of order 2 2, whose entries are from the set {0, 1, 2, 3, 4, 5}. If the sum of all the entries of A is a prime number p, 2 < p < 8, then the number of such matrices A is ___________.
Let a circle C of radius 5 lie below the x-axis. The line L1 : 4x + 3y + 2 = 0 passes through the centre P of the circle C and intersects the line L2 = 3x 4y 11 = 0 at Q. The line L2 touches C at the point Q. Then the distance of P from the line 5x 12y + 51 = 0 is ______________.
If the sum of the coefficients of all the positive powers of x, in the Binomial expansion of is 939, then the sum of all the possible integral values of n is _________.
Let , be the roots of the equation and , be the roots of the equation , > 0. If , then is equal to __________.