Electromagnetic waves are transverse in nature is evident by
Infrared radiation is detected by
In a Young’s double slit experiment the intensity at a point where the path difference is 
/6( being the wavelength of light used) is I. If I0 denotes the maximum intensity, I / I0 is equal to
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye? [Note: wavelength of light = 500 nm]
When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of the light which does not get transmitted is
If I0 is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled?
The area bounded by the x-axis, the curve y = f(x) and the lines x=1,x=b,is equal to 
for all b>1,then f(x) is
The non-zero vectors are a , b and c are related by a = 8b and c=–7b.Then the angle between a and c
The distance between two points P and Q is d and the length of their projections of PQ on the co-ordinate planes are
d1 ,d2 ,d3 .Then d2 +d2 +d2 =kd2 where‘k’is
The interval in which the function 
is decreasing is?
Let S be a finite set containing n elements. Then the total number of binary operations on S is:
An equation of the plane passing through the points (3,2,–1),(3,4,2)and(7,0,6) is 5x+3y–2z= 
,where is
A stone is dropped into a quiet lake and waves move in a circle at a speed of 3.5 cm/sec. At the instant when the radius of the circular wave is 7.5 cm. How fast is the enclosed area increasing?
A dice is tossed 5 times. Getting an odd number is considered a success. Then the variance of distribution of success is
Total number of possible matrices of order 3 × 3 with each entry 2or 0 is
A drunken man takes a step forward with probability 0.4 and backwards with probability 0.6. Find the probability that at the end of eleven steps, he is one step away from the starting point.
The resistance of 0.01 N solution of an electrolyte was found to be 220 ohm at 298 K using a conductivity cell with a cell constant of 0.88cm–1. The value of equivalent conductance of solution is –
Though the five d-orbitals are degenerate, the first four d-orbitals are similar to each other in shape whereas the fifth d-orbital is different from others. What is the designation of the fifth orbital?
How many P–H and O–H bonds respectively, are present in 
molecule?
The correct order of boiling points of 2, 2-dimethylpropane, 2-methylbutane and n-pentane is
The half life of a first order reaction is 10 min. If initial amount is 0.08 mol L-1 and concentration at some instant is 0.01 mol L-1. What is the time elapsed ?
Given the molecular formula of the hexa-coordinated complexes (i) CoCl3.6NH3, (ii) CoCl3.5NH3, (iii) CoCl3.4NH3 If the number of co-ordinated NH3 molecules in (i), (ii) and (iii) respectively are 6, 5, 4, the primary valencies in (i), (ii) and (iii) are :
A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the solution, a white precipitate is obtained which does not dissolve in dil. HNO3. The anion could be
Which one of the alkali metals, forms only, the normal oxide, M2O on heating in air ?
If the solutions of NaCl and NaNO3 are mixed in one beaker and the temperature adjusted to 383° K, the contents of the beaker will most likely:
Moissan boron is
An ‘fcc’ in a unit cell of aluminium contains the equivalent of how many atoms ?
A fire of lithium, sodium and potassium can be extinguished by
Which of the following pairs show reverse properties on moving along a period from left to right and from up to down in a group :
Which is not true for beryllium ?
The temperature of an ideal gas is reduced from 927°C to 27°C. the r.m.s. velocity of the molecules becomes.
Which one of the alkali metals, forms only, the normal oxide, M2O on heating in air ?
If the solutions of NaCl and NaNO3 are mixed in one beaker and the temperature adjusted to 383° K, the contents of the beaker will most likely:
Moissan boron is
An ‘fcc’ in a unit cell of aluminium contains the equivalent of how many atoms ?
A fire of lithium, sodium and potassium can be extinguished by
Which of the following pairs show reverse properties on moving along a period from left to right and from up to down in a group :
Which is not true for beryllium ?
The temperature of an ideal gas is reduced from 927°C to 27°C. the r.m.s. velocity of the molecules becomes.
Given the molecular formula of the hexa-coordinated complexes (i) CoCl3.6NH3, (ii) CoCl3.5NH3, (iii) CoCl3.4NH3 If the number of co-ordinated NH3 molecules in (i), (ii) and (iii) respectively are 6, 5, 4, the primary valencies in (i), (ii) and (iii) are :
A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the solution, a white precipitate is obtained which does not dissolve in dil. HNO3. The anion could be
Exactly 2 machines out of 4 are faulty. They are tested one by one in a random order till both the faulty machines are identified. Then, the probability that only two tests are required is :
Two dice are thrown together. Then the probability, that the sum of numbers appearing on them is a prime number, is
A school has four sections of chemistry in class XII having 40, 35, 45 and 42 students. The mean marks obtained in Chemistry test are 50, 60, 55 and 45 respectively for the four sections, the over all average of marks per students is
If the latusrectum of an ellipse with axis along X-axis and centre at origin is 10 and distance between foci is length of minor axis, then the equation of the ellipse is
The coefficient of x4 in the expansion of 
Locus of the points which are at equal distance from 3x + 4y – 11 = 0 and 12x + 5y + 2 = 0 and which is near the origin is
The sum of the series 3.6 + 4.7 + 5.8 + ......upto (n – 2) terms is?
The value of 
if 3f(x) - f(1 / x) = 
, then 