Q.1

The resultant of the forces acting on a body will be zero if the body

  • rotates
  • moves with variable velocity in a straight line
  • moves along a curved path
  • does not move at all.
Q.2

Ball A of massg moving on a smooth horizontal table with a velocity ofm/s hits an identical stationary ball B on the table. If the impact is perfectly elastic, the velocity of the ball B just after impact would be

  • zero
  • 5 m/sec
  • 10 m/sec
  • none of these.
Q.3

Lami's theroem states that

  • three forces acting at a point are always in equilibrium
  • if three forces acting on a point can be represented in magnitude and direction by the sides of a triangle, the point will be in the state of equilibrium
  • three coplaner forces acting at a point will be in equilibrium, if each force is proportional to the sine of the angle between the other two
  • three coplaner forces acting at a point will be in equilibrium if each force is inversely proportional to the sine of the angle between the other two
  • none of these.
Q.4

A body is said to move with Simple Harmonic Motion if its acceleration, is

  • always directed away from the centre, the point of reference
  • proportional to the square of the distance from the point of reference
  • proportional to the distance from the point of reference and directed towards it
  • inversely proportion to the distance from the point of reference
  • none of these.
Q.5

A ball moving with a velocity of 5 m/sec impinges a fixed plane at an angle ofand its direction after impact is equally inclined to the line of impact. If the coefficient of restitution is 0.the velocity of the ball after impact will be

  • 0.5 m/sec
  • 1.5 m/sec
  • 2.5 m/sec
  • 3.5 m/sec
  • 4.5 m/sec.
Q.6

For maximum range of a projectile, the angle of projection should be

  • 30°
  • 45°
  • 60°
  • none of these.
Q.7

According to Law of Triangle of Forces

  • three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force
  • three forces acting along the sides of a triangle are always in equilibrium
  • if three forces acting on a, point can be represented.in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium
  • if three forces acting at a point are in equilibrium each force is proportional to the sine of the angle between the other two
  • if the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order.
Q.8

Pick up the incorrect statement from the following. In case of suspension bridge due to rise in temperature,

  • dip of the cable increases
  • length of the cable increases
  • dip of the cable decreases
  • none of the these.
Q.9

A spring scale in a stationary lift shows a reading ofkg for a man standing on it. If the lift starts descending at an acceleration of g/the scale reading would be

  • 48 kg
  • 60 kg
  • 72 kg
  • none of these.
Q.10

One end of a light string 4 m in length is fixed to a point on a smooth wall and the other end fastened to a point on the surface of a smooth sphere of diameter 2.m and of weightkg. The reaction between the sphere and the wall of the arrangement made is

  • 102.5 kg
  • 105.5 kg
  • 108.5 kg
  • 110 kg.
Q.11

For a body moving with simple harmonic motion, the number of cycles per second, is known as its

  • oscillation
  • amplitude
  • periodic time
  • beat
  • frequency.
Q.12

A trolley wire weighs 1 kg per metre length. The ends of the wire are attached to two polesm apart. If the horizontal tension iskg, the central dip of the cable is

  • 2 cm
  • 3 cm
  • 4 cm
  • 5 cm.
Q.13

Pick up the incorrect statement from the following :

  • The C.G. of a circle is at its centre
  • The C.G. of a triangle is at the intersecton of its medians
  • The C.G. of a rectangle is at the intersection of its diagonals
  • The C.G. of a semicircle is at a distance of r/2 from the centre
  • The C.G. of an ecllipse is at the intersection of axes.
Q.14

A pilot flies a small plane in a vertical loop of radius r. At the top of its trajectory he experiences weightlessness. If the acceleration due to gravity is g, the speed of the plane at the top of its trajectory would be

  • zero
  • infinite
  • gr
  • 2gr.
Q.15

Newtons's Law of Motion is :

  • Every body continues in its state of rest or of uniform motion, in a straight line, unless it is acted upon by some external force
  • The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
  • To every action, there is always an equal and opposite reaction
  • All the above.
Q.16

A Second's pendulum gains 2 minutes a day. To make it to keep correct time its length

  • must be decreased
  • must be increased
  • is not changed but weight of the bob is increased
  • is not changed but weight of the bob is decreased
  • none of these.
Q.17

For the system of the loads shown in below figure, the time required for the 6.6 kg load to fall on the edge, is

  • 1 sec.
  • 2 sec.
  • 3 sec.
  • 4 sec.
  • 5 sec.
Q.18

If two forces acting at a point are in equilibrium, they must be equal in magnitude and their line of action must be along

  • the same line in the same sense
  • the same line in opposite sense
  • the perpendicular to both the lines
  • none of these.
Q.19

The resolved part of the resultant of two forces inclined at an angle θ in a given direction is

  • algebraic sum of the resolved parts of the forces in the direction
  • arithmetical sum of the resolved parts of the forces in the direction
  • difference of the forces multiplied by cosine θ°
  • sum of the forces multiplied by the sine θ
  • sum of the forces multiplied by the tangent θ°.
Q.20

Which one of the following laws is not applicable to a simple pendulum ?.

  • The time period does not depend on its magnitude
  • The time period is proportional to its length l
  • The time period is proportional to l where l is length
  • The time period is inversely proportional to g where g is the acceleration due to gravity.
Q.21

If two forces P and Q (P > Q) act on the same straight line but in opposite direction, their resultant, is

  • P + Q
  • P/Q
  • Q/P
  • P - Q
  • Q - P.
Q.22

If the horizontal range is 2.5 times the greatest height, the angle of projection of the projectile, is

  • 57°
  • 58°
  • 59°
  • 60°.
Q.23

Principle of Transmissibility of Forces states that, when a force acts upon a body, its effect is

  • maximum if it acts at the centre of gravity of the body
  • different at different points on its line of
  • same at every point on its line of action
  • minimum if it acts at the C.G. of the body
  • none of these.
Q.24

Akg lady stands on a spring scale in an elevator. During the first 5 sec, starting from rest, the scale readskg. The velocity of the elevator will be

  • 10 m/sec
  • 15 m/sec
  • 20 m/sec
  • 25 m/sec.
Q.25

The reaction at the support B of the beam shown in below figure is

  • 1.6 t
  • 9.6 t
  • 8.5 t
  • 0.5 t.
Q.26

The motion of a particle is described by the relation x = t2- 10t +where x is in metres and t in seconds. The total distance travelled by the particle from t = 0 to t =seconds would be

  • zero
  • 30 m
  • 50 m
  • 60 m
  • none of these.
Q.27

The following is not a law of static friction :

  • The force of friction always acts in a direction opposite to that in which the body tends to move
  • The force of friction is dependent upon the area of contact
  • The force of friction depends upon the roughness of the surface
  • The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces.
Q.28

One end of a light string 4 m in length is fixed to a point on a smooth wall and the other end fastened to a point on the surface of a smooth sphere of diameter 2.m and of weightkg. The tension in the string is

  • 17.5 kg
  • 19.5 kg
  • 22.5 kg
  • 25 kg.
Q.29

For lifting a load ofkg through a distance of 2.5 cm, an effort of 12.5 kg is moved through a distance ofcm. The efficiency of the lifting machine, is

  • 60%
  • 65%
  • 70%
  • 25%.
Q.30

If the angle between the applied force and the direction of motion of a body, is betweenand 180°, the work done, is called

  • virtual work
  • imaginary work
  • zero work
  • negative work.
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