2013
PHYSICS
Time: 3 Hours 15 Minutes] [Full Marks: 80
Instructions to candidates:
Special credit will be given for answers which are brief and to the point.
Marks will be deducted for spelling mistakes, untidiness and bad handwriting.
Figures in the margin indicate full marks for the questions.
GROUP – A
1. Answer the following questions either in one word or in one sentence (Alternative
are to be noted): 1 x 10 = 10
a) What is the angular speed of second hand of a watch?
b) Define universal gravitational constant.
OR
Magnitudes of acceleration due to gravity at a height h and at a depth x from the
earth’s surface are the same. Write down the relation between x and h (x and h
are very small in comparison to the radius of the earth).
c) Can light wave be longitudinal?
d) The equation of a progressive wave is y=A sin (kx – ωt). What is the maximum
value of velocity of a particle on the wave?
OR
The wavelength of a wave is 2m.What is the phase difference between two points
on a wave separated by 1m in the medium?
e) How much work is done in moving q coulomb of charge between two points
separated by a distance r on an equipotential surface?
OR
Fill in the blanks:
The surface density of charge of a charged conductor placed in air is σ. Electric
