1.
The pair having the same
dimensions is a) Angular momentum ,
work b) Work, torque c) Potential energy , linear momentum d) Kinetic energy , velocity
2.
Which one has the dimension
different from the remaining three a)
Power b) Work c) Torque d) Energy
3.
Torr is the unit of a) Pressure b) Volume c) Density d) Flux
4.
Which one is a vector : a)
Length b) Volume c) Velocity d) Work
5.
The magnitude of the vector 2/3
i –1/3 j + 2/3 k is : a) Zero b) One c)
Three d) 1/9
6.
If the x- component of a vector
is positive and y- component is negative , then resultant vector lies in what
quadrant : a) 1st quadrant b)
2nd quadrant c) 3rd
quadrant d) 4th quadrant
7.
Slope of velocity time graph is
: a) Acceleration b) Distance c)
Force d) Momentum
8.
Which law of motion is also
called law of inertia ? a) 1 st law b) 2 nd law c) 3rd law d) 4th law
9.
Momentum depends on a) Force
acting on the body b) Mass of the body
c) Velocity of the body d) Both
mass and velocity of the body
10. Area under the curve of force-displacement graph is equal to : a)
Displacement b) Work c) Power d) Energy
11. When a force is parallel to the direction of motion of the body ,
then work done on the body is : a) zero
b) minimum c) infinity d) Maximum
12. Power is also defined as dot product of a) Force and
displacement b) Force and mass c) Force and velocity d) Force and time
13. Moment of inertia is equal to : a) m^2 r b) m^2 r^2
c) m r d) m r^2
14. The rate of change of angular displacement is called : a) Angular displacement b) Angular velocity c) Angular acceleration d) Torque
15. Centripetal force
performs a) Maximum work b) Minimum work c) Negative work d) no work
16. When torque acting on system is zero , which of the following will
be constant : a) Linear momentum b)
Force c) Angular momentum d) impulse
17. Geo-stationary satellite completes one rotation around earth is : a)
3 hours b) 6 hours c) 12 hours d) 24 hours
18. If a body of mass 10 kg is allowed to
fall freely , its weight becomes a) zero
b) 98 N c) 9.8 N d) 10 N
19. The apparent weight of a man in an
ascending lift moving with acceleration ‘a’
a) Increases b) decreases c)
Remains constant d) Becomes zero
20. A particle is moving in a circle with constant
speed . The direction of centripetal force will be a) Along tangent b) Along radius towards center c) Along
radius away from center d) Changing with
motion
21. The escape velocity from the earth
surface in km/s is : a) 4.2 km/s b) 7.5 km/s c) 9.5 km/s d) 11 km/s
22. Motion of projectile is ----------
dimensional a) One b) Two
c) Three d) Four
23. Inertia of an object is quantitative
measure of its : a) Volume b) Density c)
Mass d) Temperature
24. When velocity time graph is a straight
line parallel to the time axis then : a) Acceleration is const b) Acceleration is variable c) Acceleration is zero d) Velocity is zero
25 . The direction of torque can be found
by : a) Head and tail rule b) Right hand
rule c) Left hand rule d) Fleming rule
Section – B
Answer the following questions with few
words : 2 x 6 = 12
26. Define S.I unit of solid angle .
27. What is the relative velocity of two
bodies having equal velocities ?
28.Two vectors A and B are perpendicular to each
other . What is the value of A.B ?
29.When an air buble rises in water , what
happens to its potential energy ?
30. A wheel 0.5 m in radius is moving with
a speed of 12m/s . Find its angular
speed .
31. Why is gravitational potential energy always
negative ?
Answer the following questions briefly
. 3 x 6 = 18
32. At what height above the surface of the
earth , the value of acceleration due to gravity is reduced to one fourth of its value on the
surface of earth ?
33.Find the dimension of latent heat and
specific heat .
34. A particle is thrown upwards . It
attains a height (h) after 5 seconds and again after 9 s comes back . What is
the speedof the particle at height h ?
35. Prove that the centre of mass of two
particles divides the line joining the particles in the inverse of their masses
.
36. Find the radius of gyration of a solid
sphere about its diameter .
37 . A thief jumps from the roof of a house with a
box of weight W on his head. What will
be the weight of the box as experienced by the thief during jump?
Section – C
Directions: Each of these questions contain two statements, Assertion and Reason.
Each of these questions also has four alternative choices, only one of which is
the correct answer. You have to select one of the codes (a), (b), (c) and (d)
given below.
(a) Assertion is correct, reason is correct; reason is a correct
explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct
explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct. 1 x 5 = 5
38. Assertion: A body loses weight when it is at the centre of
the earth.
Reason: At the centre of earth, g = 0. Therefore, weight = mg = 0.
39. Assertion : If earth suddenly stops rotating about its axis,
then the value of acceleration due to gravity will become same at all the
places.
Reason : The value of acceleration due to gravity depends upon the rotation of
the earth.
40. Assertion : Gravitational force between two particles is
negligibly small compared to the electrical force.
Reason : The electrical force is experienced by charged particles only.
41. Assertion : The centre of mass of a body may lie where there
is no mass.
Reason : Centre of mass of body is a point, where the whole mass of the body is
supposed to be concentrated.
42. Assertion : Two particles of different mass, projected with
same velocity at same angles. The maximum height attained by both the particle
will be same.
Reason : The maximum height of projectile is independent of particle mass.
Section – D
43. Read the passage below
answer the questions that follow : 1x 5 = 5
Kinematics is the branch of mechanics which deals with the study of
motion of material
objects without taking into account the factors affecting the motion.
Rest and motion are
relative concept and nothing is absolute. The Position of the object at
a given instant of time
is described in terms of position coordinates. The coordinate system
along with a clock
constitutes a frame of reference. Frame of reference can be of two types
viz: inertial frame of
reference and non-inertial frame of reference. When position of body
change in a frame of
reference, it is said to be in motion which is categorised as uniform
and non-uniform. Motion
of a body is studied in terms of position-time graph and velocity-time
graph.
(i) "Rest and motion are relative not absolute." Comment.
(ii) What are different types of frames of reference? Explain.
(iii) Draw position-time graph for uniform and Non-uniform motion.
(iv) Draw velocity-time graph for uniform and non-uniform motion.
(v) Relative veolcity of two bodies is zero. What is nature of
Position-time graph for it?
Section – E
Answer the following questions : 5 x7 = 35
44. The unit of length convenient
on the nuclear scale is a feri : 1 f = 10^-15 m . Nuclear sizes objects roughly
obey the following empirical relation : r = r° A^1/3 , r is the radius of the
nucleus , A its mass number r° is a constant equal to 1.2 f . Show that the
rule implies that nuclear mass density is nearly constant for different nuclei
.
45. A balloon is
ascending at the rate of 4.9m/s. A pocket is dropped from the balloon when
situated at a height of 245m. How long does it take the packet to reach the
ground? What is its final velocity?
46. A
particle starts from the origin at t = 0 s
with a velocity of 10j m/s and
moves in the x-y plane with a constant acceleration of (8i + 2j) m/s^2
a) At what
time is the x-coordinate of the particle 16 m ? What is the y-coordinate of the
particle at that time?
47. Why is horizontal velocity constant in
projectile motion? Why are two projection angles possible for the same range?
48. If speed doubles, what happens to kinetic
energy? If the same bullet emerges with 10% of its initial kinetic energy, find
its speed.
49. What is the relation between
linear velocity and angular velocity? Why do particles on the axis of rotation
remain stationary?
50. Why is g maximum at Earth’s
surface?
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