Question

Model Question SET I
B MODEL QUESTION, 2076
Subject: Physics
Time: 3 hours
F.M.: 75
P.M.:27
You may use the following values of physical constants wherever necessary:
Young modulus for steel = 2x1011Nm-2
Specific heat capacity of copper= 390 Jkg-1
k
-1
Specific heat capacity of Iron =470 Jkg-1
k
-1
Specific heat capacity of water = 4190 Jkg-1
k
-1
Universal gas constant= 8.31 J Mol-1k-1
Thermal conductivity of Aluminium = 205.0 Wm-1
k
-1
Thermal conductivity of Brass = 109.0 Wm-1
k
-1
Charge of electron = 1.6x10-19c
Mass of electron = 9.1x10-31kg
Group 'A'
1. Answer in brief, any six questions: 6x2=12
a) The diameter of a steel rod is given as 56.47 ± 0.02 mm. What does it mean?
b) If the displacement of a body is proportional to square of time, state whether
the body is moving with uniform velocity or uniform acceleration.
c) Does the centre of gravity of a solid body always lie within the material of the
body? Explain with an example.
d) Why is it more difficult to revolve a stone by tying it to a longer string than
by tying it to a shorter string?
e) An astronaut in a space capsule orbiting the earth experiences weightlessness.
Why?
f) Why are small liquid drops spherical while large drops are flat?
g) Why is it easier to pull a body than to push it?
2. Answer, in brief, any two questions: 2x2=4
a) What is a triple point? Show that there exists a single value of triple point.
b) Why is the specific heat capacity of gas at constant pressure greater than
its specific heat capacity at constant volume?
c) Explain on the basis of kinetic theory that the pressure of a gas increases
with increase of temperature.
3. Answer, in brief, any one question: 2
a) What is illuminance? Does the direction of incidence of light affect the
illuminance of the surface? Explain.
b) A lens is immersed in water. Is there any change in its focal length?
4. Answer, in brief, any one question: 2
a) Why do bodies get electrified when they are rubbed together for a while?
b) Can we give any desired quantity of charge to a capacitor?
Group 'B'
5. Answer any three questions: 3x4=12
a) Define centripetal and centrifugal forces. Derive an expression for the
force acting on a body moving with uniform speed along a circular path.
b) Write expressions for work done by a constant and a variable force. Show
that the work done by the resultant force on a particle is equal to the
change in kinetic energy of the particle.

Answer 1

Answer:

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