Question & Answer

The most suitable reagent for the conversion of R − CH2 − OH → R − CHO is :

Which one is classified as a condensation polymer?

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is :

The major organic compound formed by the reaction of 1, 1, 1 − trichloroethane with silver powder is :

Which one of the following bases is not present in DNA?

The correct statement for the molecule, CsI3, is :

On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide, the organic compound formed is

For the reaction SO2(g) + 1 O2(g)

For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid  required 20 mL of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is :

CsCl crystallises in body centred cubic lattice. If ‘a’ is its edge length then which of the
following expressions is correct ?

Resistance of 0.2 M solution of an electrolyte is 50 Ω. The specific conductance of the solution is 1.4 S m−1. The resistance of 0.5 M solution of the same electrolyte is 280 Ω. The molar conductivity of 0.5 M solution of the electrolyte in S m2 mol−1 is :

Consider separate solutions of 0.500 M C2H5OH(aq), 0.100 M Mg3(PO4)2(aq), 0.250 M KBr(aq) and 0.125 M Na3PO4(aq) at 25°C. Which statement is true about these solutions, assuming all salts to be strong electrolytes ?

If Z is a compressibility factor, van der Waals equation at low pressure can be written as

The metal that cannot be obtained by electrolysis of an aqueous solution of its salts is :

The de-Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 m/s is approximately?

[Planck's constant, h = 6.63 x 10^-34 Js] 

In Bohr series of lines of the hydrogen spectrum, the third line from the red end corresponds to which one of the following inner orbit jumps of electron for Bohr's orbit in atom of hydrogen?

If the straight lines  and  intersect at a point, then the integer k is equal to

The line passing through the points (5, 1, a) and (3, b, 1) crosses the yz­plane at the point  Then

Let L be the line of intersection of the planes 2x + 3y + z = 1 and x + 3y + 2z = 2. If L makes an angle a with the positive x-­axis, then cos a equals

Let  and  If the vectors  lies in the plane of  and , then x equals

If (2, 3, 5) is one end of a diameter of the sphere x² + y² + z² – 6x – 12y – 2z + 20 = 0, then the coordinates of the other end of the diameter are

If a line makes an angle of  with the positive directions of each of x­axis and y­axis, then the angle that the line makes with the positive direction of the z­axis is

The image of the point (–1, 3, 4) in the 3 plane x – 2y = 0 is

The two lines x = ay + b, z = cy + d and x = a'y + b', z = c'y + d' are perpendicular to each other if

The angle between the lines 2x = 3y = –z and 6x = –y = –4z is

The plane x + 2y – z = 4 cuts the sphere x² + y² + z² – x + z – 2 = 0 in a circle of radius

If the angle  between the line  and the plane  is such that sin  = 1/3 the value of is

A 20 g bullet pierces through a plate of mass m1 = 1 kg and then comes to rest inside a second plate of mass m2 = 2.98 kg. It is found that the two plates, initially at rest, now move with equal velocities. The percentage loss in the initial velocity of bullet when it is between m1 and m2. (Neglect any loss of material of the bodies, due to action of bullet.) will be

If the straight lines x = 1 + s, y = –3  z = 1 +  and x = t/2, y = 1 + t, z = 2 – t, with parameters s and t respectively, are co­planar, then  equals

A bullet of mass 10g travelling horizontally with a velocity of 300 m/s strikes a block of wood of mass 290 g which rests on a rough horizontal floor. After impact the block and the bullet move together and come to rest when the block has travelled a distance of 15 m. The coefficient of friction between the block and the floor will be - (Duration of impact is very short)

The eccentricity of an ellipse, with its centre at the origin, is 1/2. If one of the directrices is x = 4, then the equation of the ellipse is

The intercept on the line y = x by the circle x² + y² – 2x = 0 is AB. Equation of the circle on AB as diameter is

If the lines 2x + 3y + 1 = 0 and 3x – y – 4 = 0 lie along diameters of a circle of circumference  then the equation of the circle is

A line with direction cosines proportional to 2, 1, 2 meets each of the lines x = y + a = z and x + a = 2y = 2z. The co­ordinates of each of the points of intersection are given by

Distance between two parallel planes 2x + y + 2z = 8 and 4x + 2y + 4z + 5 = 0 is

A line makes the same angle  with each of the x and z axis. If the angle  which it makes with y­axis, is such that  then  equals:

The lines  are copolar only if

The two lines x = ay + b, z = cy + d and x = a'y + b', z = c'y + d will be perpendicular, if and only if

If  = 0 and vectors   and  are non­-coplanar, then the product abc equals

A tetrahedron has vertices at O (0, 0, 0), A (1, 2, 1), B (2, 1, 3) and C (–1, 1, 2). Then the angle between the faces OAB and ABC will be

The radius of the circle in which the sphere x² + y² + z² + 2x – 2y – 4z – 19 = 0 is cut by the plane x + 2y + 2z + 7 = 0 is

What is the shortest distance from the plane 12x + 4y + 3z = 327 to the sphere x² + y² + z² + 4x – 2y – 6z = 155?

Two systems of rectangular axes have the same origin. If a plane cuts them at distance a, b, c and a', b', c' from the origin, then

The d.r. of normal to the plane through (1, 0, 0), (0, 1, 0) which makes an angle  with plane x + y = 3 are