1. The error in the measurement of radius of the sphere is 2%. What
would be the error in the volume of the sphere?(1)
2. A ball is thrown up in a moving train; it comes back to the person’s
hands. Why? (1)
3. An electron of mass ‘m’ is moving a circular orbit around a nucleus of
radius 10 -15m. Calculate the work done by the attractive force towards
the nucleus.
(1)
4. A body is rotating at a steady rate. Is any torque acting on the body?
Why?
(1)
5. The value of ‘g’ is maximum or minimum at poles? Why? (1)
6. What happens to the change in internal energy of a gas during
isothermal expansion? (1)
7. In the graph PV/T versus P for 1 g Oxygen gas at two different
temperatures T1 and T 2, represented by curves AD and AC respectively.
The plot ‘AB’ signifies the ideal behavior of the gas. Which is true:
T1 > T2 or
T1 < T2 ? Why?
(1)
T1
A
C
D
B
T2
8. Why strings of different thicknesses and materials are used in a sitar or
a violin?
(1)
9. SONAR uses ultra-sonic waves to detect and locate objects under water.
In a submarine equipped with SONAR, the time delay between the
generation of a probe wave and the reception of its echo after
reflection from an enemy submarine is found to be 60 s. What is the
distance of the enemy submarine?(Given the velocity of SONAR =1450
m/s) (2)
10. The position-time graphs of two objects make angles of 30 and 60 with
time axis. Find the ratio of their velocities. (2)
11. An aircraft executes a horizontal loop at a speed of 200 m/s. with its
wings banked at 15 degree. What is the radius of the loop? (2)
12. A variable force makes displacement o f‘s’ along the direction of the
application of force. How will you determine the work done with the
help of graphical representation? (2)
13. The moments of inertia of two rotating bodies A and B are I A and I B.
(I A > I B) and their angular momenta are equal. Which one has a greater
kinetic energy?
(2)
14.Show mathematically that a man can jump on the moon six times as
high as on earth. (2)
15.Represent graphically the variation of extension with load in an elastic
body. On the graph, mark (a) Hooke’s law region (b) Elastic limit
(c) Yield point and (d) Breaking point. (2)
16.At what temperature does all molecular motion cease? Give reason. (2)
17. Define degrees of freedom? Calculate the number of degrees of
freedom, does a monoatomic gas molecule has? (2)
18.The frequency of oscillation of a mass ‘m’ suspended by a spring is ‘γ1’.
If the length of the spring is cut to one half, the same mass oscillates
with frequency ‘γ2’. Find the ratio of ‘γ1 ‘ to ‘ γ2’.
(2)
OR
Why does a simple pendulum make damped oscillations? Plot the graph
of damped and un-damped oscillations. (2)
19.A projectile is fired from the ground, following parabolic path. Obtain an
expression for maximum height attained. Why does the direction of
motion of a projectile become horizontal at the height point of its
trajectory? (3)
20.What is an elastic collision? A neutron makes head-on collision with a
deuteron at rest and sticks to it, and the combination moves along the
same straight line keeping the momentum conserved. Write an
expression for the velocity of the combination. (3)
21.Distinguish between conservative and non- conservative forces. Give an
example each. (3)
22.A pull of 15 N is applied to a rope attached to a block of mass 7 Kg lying
on the smooth horizontal plane. The mass of the rope is 0.5 kg. What is
the force exerted by the block on the rope? (3)
23.Draw a plot of spring force versus displacement. Hence find an
expression for the potential energy of an elastic spring. (3)
24.(i) Show that power consumed by a rigid body in rotational motion if the
product of torque and angular momentum. (ii) A solid cylinder of mass
20 kg rotates about its axis with angular speed of 100 rad/s. The radius
of the cylinder is 0.1m. What is the kinetic energy associated with the
rotation of the cylinder?
(3)
25.(i) On what factors does the escape velocity of an object depend?
(ii) Suppose there exist a planet that went around the sun twice as fast
as earth. What would be its orbital size as compared to that of earth?
( Given radius of earth = 1 AU)
(3)
26.In a test experiment on a model aero plane in a wind tunnel, the flow
speeds on the upper and lower surfaces of the wings are 70 m/s and 63
m/s respectively. What is the lift of the wing if its area is 2.5 m2 ?
Density of air = 1.3 Kg m-3 . (3)
27.Apply first law of thermodynamics to get the relation between the two
specific heats of a gas. (3)
28.State parallel o gram law of vector addition and find the magnitude and
direction of the resultant of the two vectors P and Q inclined at an angle
θ with each other. What happens when θ = 00 and θ = 00 . (5)
OR
(i)
A body is in uniformly accelerated motion along a straight line in
one dimension. Plot the velocity - time graph of the motion and
deduce the equation of motion connecting the distance travelled
and time‘t’ taken to travel.
(ii) If the body travels equal distance with uniform negative
acceleration, in the same time‘t’ in the opposite direction, calculate the
net displacement and distance covered during the motion. (5)
29.(a) Define terminal velocity. Obtain an expression for terminal velocity
of a sphere of radius ‘r’, density ‘ρ’ falling vertically through a viscous
fluid of density ‘σ’ and coefficient of viscosity ἠ
(3)
(b) A rain drop of radius 0.3 mm falls through air with a terminal velocity
of 1 m/s. The viscosity of air is 18 x 10-5 poise. Find the viscous force on
the rain drop.
(2)
OR
(a) Prove that Surface tension is numerically equal to surface energy.
Also mention an experiment to demonstrate the measurement of
surface tension.
(3)
(b) Mercury has an angle of contact equal to 140 0 with soda lime glass.
A narrow tube of radius 1 mm made of the glass is dipped in a trough
containing mercury. By what amount does the mercury dip down in
the tube relative to the liquid surface outside? Surface tension of
mercury is 0.465 N/m. Density of mercury = 13.6 x 10 kgm-3 .
(Hint: cos 1400 = - cos 400 )
(2)
30.What are beats? Explain the formation of beats analytically. Prove that
the beat frequency is equal to the difference in frequencies of the two
superposing waves.
(5)
OR
Draw fundamental modes of vibration of stationary waves in (i) Closed
pipe (ii) open pipe. Derive an expression for the formation of harmonics
of standing waves in a stretched string. (5)