Applied Mechanics objective question and answer

Question No. 01

Select the correct statement

(A)   The body centrode rolls on the space centrode

(B)   The space centrode rolls on the body centrode

(C)   Both body and space centrodes may role on each other

(D)   The body centrode never touches space centrode 

Answer: Option A

 

Question No. 02

The following is in unstable equilibrium

(A)   A uniform solid cone resting on a generator on a smooth horizontal plane

(B)   A uniform solid cone resting on its base on a horizontal plane

(C)   A solid cube resting on one edge

(D)   A satellite encircling the earth

Answer: Option C

 

Question No. 03

In a lifting machine with efficiency 60%, an effort of 200 N is required to raise a load of 6 kN. The velocity ratio of the machine is

(A)   30

(B)   50

(C)   60

(D)   80

Answer: Option B

 

Question No. 04

The member forces in a statically in determinate truss

(A)   Can be obtained by graphic statics

(B)   Cannot be obtained by graphic statics

(C)   May be obtained by graphic statics

(D)   Can be obtained by graphic statics by trial and error

Answer: Option B

 

Question No. 05

A ball moving on a smooth horizontal table hits a rough vertical wall, the coefficient of restitution between ball and wall being 1/3. The ball rebounds at the same angle. The fraction of its kinetic energy lost is

(A) 1/3

(B) 2/3

(C) 1/9

(D) 8/9

Answer: Option D

 

Question No. 06

A heavy ladder resting on floor and against a vertical wall may not be in equilibrium if

(A)   Floor is smooth and wall is rough

(B)   Floor is rough and wall is smooth

(C)   Both floor and wall are rough

(D)   Both floor and wall are smooth

Answer: Option D

 

Question No. 07

The maximum displacement of a particle executing S.H.M. corresponds to

(A)   Zero potential energy and maximum kinetic energy

(B)   Zero kinetic energy and maximum potential energy

(C)   Maximum kinetic energy and maximum potential energy

(D)   Minimum kinetic energy and minimum potential energy

Answer: Option B

 

Question No. 08

A sphere and a cylinder having the same mass and radii start from rest and roll down the same inclined plane. Which body gets to the bottom first?

(A)   Sphere with greater rotational energy at bottom than cylinder

(B)   Sphere with lesser rotational energy at bottom than cylinder

(C)   Cylinder with greater rotational energy at bottom than sphere

(D)   Both reach the bottom simultaneously with equal rotational energy at bottom 

Answer: Option B

 

Question No. 09

When a circular wheel rolls on a straight track, then the shape of body centrode and space centrode respectively are

(A)   Straight line and parabola

(B)   Straight line and circle

(C)   Circle and straight line

(D)   Circle and parabola

Answer: Option C

 

Question No. 10

The time period of a simple pendulum depends on

(i) Mass of suspended particle

(ii) Length of the pendulum

(iii) Acceleration due to gravity The correct answer is

(A)   Only (i)

(B)   Both (ii) and (iii)

(C)   Both (i) and (iii)

(D)   All are correct

Answer: Option B

Question No. 11

A light rope is loaded with many equal weights at equal horizontal intervals. The points of suspension on the rope lie on a

(A)   Parabola

(B)   Catenary

(C)   Cycloid

(D)   Ellipse 

Answer: Option A

 

Question No. 12

Free body diagram is an

(A)   Isolated joint with only body forces acting on it

(B)   Isolated joint with internal forces acting on it

(C)   Isolated joint with all the forces, internal as well as external, acting on it

(D)   None of the above

Answer: Option C

 

Question No. 13

The graphical method of determining the forces in the members of a truss is based on

(A)   Method of joint

(B)   Method of section

(C)   Either method

(D)   None of the two methods

Answer: Option A

 

Question No. 14

In which of the following trusses, the method of substitution is required for determining the forces in all the members of the truss by graphic statics?

(A)   Howe truss

(B)   King post truss

(C)   Fink truss

(D)   Warren truss 

Answer: Option C

 

Question No. 15

If the direction of projection bisects the angle between the vertical and the inclined plane, then the range of projectile on the inclined plane is

(A)   Zero

(B)   Maximum

(C)   Minimum

(D)   None of these

Answer: Option B

Question No. 16

A particle executes a simple harmonic motion. While passing through the mean position, the particle possesses

(A)   Maximum kinetic energy and minimum potential energy

(B)   Maximum kinetic energy and maximum potential energy

(C)   Minimum kinetic energy and maximum potential energy

(D)   Minimum kinetic, energy and minimum potential energy

Answer: Option A

 

Question No. 17

The tension in a cable supporting a lift

(A)   Is more when the lift is moving downwards

(B)   Is less when the lift is moving upwards

(C)   Remains constant whether its moves downwards or upwards

(D)   Is less when the lift is moving downwards 

Answer: Option D

 

Question No. 18

The vertical reaction at the support of the structure shown in below figure, is 

(A)   1 t

(B)   2 t

(C)   3 t

(D)   3.5 t

Answer: Option C

 

Question No. 19

The shape of a suspended cable under its own weight, is

(A)   Parabolic

(B)   Circular

(C)   Catenary

(D)   Elliptical 

Answer: Option C

Question No. 20

If the kinetic energy and potential energy of a simple harmonic oscillator of amplitude A are both equal to half the total energy, then the displacement is equal to

(A)   A

(B)   A/2

(C)  
A/√2

(D)  
A

Answer: Option C

 

Question No. 21

Pick up the correct statement from the following:

(A)   If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities

(B)   If a sphere impinges directly on an equal sphere which is at rest, then a fraction ½(1 - e²) the original kinetic energy is lost by the impact

(C)   If two equal spheres which are perfectly elastic impinge at right angles, their direction after impact will still be at right angles

(D)   All the above 

Answer: Option D

 

Question No. 22

The inherent property of a body which offers reluctance to change its state of rest or uniform motion, is

(A)   Weight

(B)   Mass

(C)   Inertia

(D)   Momentum 

Answer: Option C

 

Question No. 23

A particle is executing simple harmonic motion in a line 1.0 m long. If the time of one complete vibration is 1 sec, then the maximum velocity of the particle is

(A)   1.00 m/sec

(B)   1.57 m/sec

(C)   3.14 m/sec

(D)   6.28 m/sec 

Answer: Option C

 

Question No. 24

Pick up the correct statement from the following. The kinetic energy of a body

(A)   Before impact is equal to that after impact

(B)   Before impact is less than that after impact

(C)   Before impact is more than that after impact

(D)   Remain constant 

Answer: Option C

Question No. 25

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

(A)   2 t

(B)   5.8 t

(C)   0.2 t

(D)   3.5 t

Answer: Option A

 

Question No. 26

Three forces which act on a rigid body to keep it in equilibrium. The forces must be coplanar and

(A)   Concurrent

(B)   Parallel

(C)   Concurrent parallel

(D)   None of these

Answer: Option A

 

Question No. 27

Coefficient of friction depends on

(A)   Nature of surfaces only

(B)   Area of contact only

(C)   Both (A) and (B)

(D)   None of the above

Answer: Option A

 

Question No. 28

The intrinsic equation of catenary is

(A)  
S = c         

(B)   y = c cosh x/c

(C)  
y = c           

(D)  
y = c

Answer: Option A

 

Question No. 29

If a particle is projected inside a horizontal tunnel which is 554 cm high with a velocity of 60 m per sec, the angle of projection for maximum range, is

(A)   8°

(B)   9°

(C) 10°

(D) 11°

Answer: Option C

 

Question No. 30

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

(A) 10.8 t

(B) 10.6 t

(C) 10.4 t

(D) 10.2 t

Answer: Option A

 

Question No. 31

The maximum pull in a cable, carrying a uniformly distributed load and supported at two ends which are at the same level, is at

(A)   Supports

(B)   Quarter span

(C)   Mid span

(D)   None of the above

Answer: Option A

 

Question No. 32

A stone is whirled in a vertical circle, the tension in the string, is maximum

(A)   When the string is horizontal

(B)   When the stone is at the highest position

(C)   When the stone is at the lowest position

(D)   At all the positions

Answer: Option C

 

Question No. 33

At a given instant ship 'A' is travelling at 6 km/h due east and ship 'B' is travelling at 8 km/h due north. The velocity of  'B relative to 'A' is

(A)   7 km/hrs

(B)   2 km/hrs

(C)   1 km/hrs

(D)   10 km/hrs 

Answer: Option D

 

Question No. 34

The ratio of the moment of inertia of a rectangle about its centroidal axis to the moment of inertia about its base, is

(A) 1/4

(B) 1/2

(C) 3/4

(D) 2

Answer: Option A

 

Question No. 35

The angular speed of a car taking a circular turn of radius 100 m at 36 km/hr will be

(A)   0.1 rad/sec

(B)   1 rad/sec

(C)   10 rad/sec

(D)   100 rad/sec 

Answer: Option A

 

Question No. 36

A weight 'W' is suspended at the free end of a light member hinged to a vertical wall. If the angle of inclination of the member with the upper wall is θ°, the force introduced in the number is, 

(A)  secθ

(B)  W cosθ

(C)  W sinθ

(D)   W cosecθ

Answer: Option A

 

Question No. 37

The beam shown in below figure is supported by a hinge at 'A' and a roller at 'B'. The reaction R_A of the hinged support 'A' of the beam, is

(A) 10.8 t

(B) 10.6 t

(C) 10.4 t

(D) 10.2 t

Answer: Option D

 

Question No. 38

Two particles have been projected at angles 64° and 45° to the horizontal. If the velocity of projection of first is 10 m/sec, the velocity of projection of the other for equal horizontal ranges is

(A)   9.3 m/sec

(B)   8.3 m/sec

(C)   7.3 m/sec

(D)   6.3 m/sec

Answer: Option A

 

Question No. 39

The force polygon representing a set of forces in equilibrium is a

(A)   Triangle

(B)   Open polygon

(C)   Closed polygon

(D)   Parallelogram

Answer: Option C

 

Question No. 40

The centre of gravity of a homogenous body is the point at which the whole

(A)   Volume of the body is assumed to be concentrated

(B)   Area of the surface of the body is assumed to be concentrated

(C)   Weight of the body is assumed to be concentrated

(D)   All the above

Answer: Option C

 

Question No. 41

A satellite moves in its orbit around the earth due to

(A)   Gravitational force

(B)   Centripetal force

(C)   Centrifugal force

(D)   None of these

Answer: Option B

 

Question No. 42

The force acting on a point on the surface of a rigid body may be considered to act

(A)   At the centre of gravity of the body

(B)   On the periphery of the body

(C)   On any point on the line of action of the force

(D)   At any point on the surface normal to the line of action of the force

Answer: Option C

 

Question No. 43

For a non-concurrent force system to be in equilibrium

(A)   Only the closure of force polygon is sufficient

(B)   Only the closure of funicular polygon is sufficient

(C)   Both force polygon and funicular polygon must close

(D)   None of the above

Answer: Option C

 

Question No. 44

If 'l' is the span of  a light suspension bridge who's each cable carries total weight (w) and the

central dip is 'y', the horizontal pull at each support, is

(A)   wl/4y

(B)   wl/8y

(C)   wl/2y

(D)   wl

Answer: Option B

 

Question No. 45

The C.G. of the shaded area of the below figure whose curve OM is a parabola from y-axis, is

(A)   a/4

(B)   3a/4

(C) 3b/10

(D) 3a/10 

Answer: Option B

 

Question No. 46

A rod 5 m in length is moving in a vertical plane. When it is inclined at 60° to horizontal, its lower end is moving horizontally at 3 m/sec and upper end is moving in vertical direction. The velocity of its upper end, is

(A)   0.5 m/sec

(B)   1.0 m/sec

(C)   1.5 m/sec

(D)   2.5 m/sec 

Answer: Option B

 

Question No. 47

A force P of 50 N and another force Q of unknown magnitude act at 90° to each other. They are balanced by a force of 130 N. The magnitude of Q is

(A)   60 N

(B)   80 N

(C)   100 N

(D)   120 N 

Answer: Option D

 

Question No. 48

On a mass 'm' describing a circular path of radius 'r' , the centrifugal force

(A)   Acts tangentially to the circular path

(B)   Acts towards the centre of rotation

(C)   Acts away from the centre of rotation

(D)   Is mw^2r/g kgf 

Answer: Option B

 

Question No. 49

Parallelogram Law of Forces states, "if two forces acting simultaneously on a particle be represented in magnitude and direction by two adjacent sides of a parallelogram, their resultant may be represented in magnitude and direction by

(A)   Its longer side

(B)   Its shorter side

(C)   The diagonal of the parallelogram which does not pass through the point of intersection of the forces

(D)   The diagonal of the parallelogram which passes through the point of intersection of the forces

Answer: Option D

 

Question No. 50

The following factor affects the orbit of a satellite up to an altitude of 720 km from the earth's surface

(A)   Uneven distribution of the gravitational field

(B)   Gravity of the sun and the moon

(C)   Aerodynamic forces

(D)   None of these 

Answer: Option D

 

Question No. 51

Two circular discs of same weight and thickness are made from metals having different densities. Which disc will have the larger rotational inertia about its central axis?

(A)   Disc with larger density

(B)   Disc with smaller density

(C)   Both discs will have same rotational inertia

(D)   None of the above 

Answer: Option B

 

Question No. 52

Moment of inertia of a squares of side 'b' about an axis through its centre of gravity, is

(A) b³/4

(B) b⁴/12

(C)   b⁴/3

(D)   b⁴/8

Answer: Option B

 

Question No. 53

The masses of two balls are in the ratio of 2 : 1 and their respective velocities are in the ratio of 1 : 2 but in opposite direction before impact. If the coefficient of restitution is ½, the velocities of separation of the balls will be equal to

(A)   Original velocity in the same direction

(B)   Half the original velocity in the same direction

(C)   Half the original velocity in the opposite direction

(D)   Original velocity in the opposite direction 

Answer: Option D

 

Question No. 54

The ratio of the reactions R_A and R_B of a simply supported beam shown in below figure is

(A) 0.50

(B) 0.40

(C) 0.67

(D) 1.00

Answer: Option D

 

Question No. 55

A disc of mass 4 kg, radius 0.5 m and moment of inertia 3 kgm² rolls on a horizontal surface so that its center moves with speed 5 m/see. Kinetic energy of the disc is

(A)   50 J

(B)   150 J

(C)   200 J

(D)   400 J 

Answer: Option C

 

Question No. 56

A point subjected to a number of forces will be in equilibrium, if

(A)   Sum of resolved parts in any two directions at right angles, are both zero

(B)   Algebraic sum of the forces is zero

(C)   Two resolved parts in any two directions at right angles are equal

(D)   Algebraic sum of the moments of the forces about the point is zero

Answer: Option A

 

Question No. 57

The resultant of two forces 'P' and 'Q' acting at an angle θ is

(A)   P² + Q² + 2P sinθ

(B)  P² + Q² + 2PQ cosθ

(C)  P² + Q² + 2PQ tanθ

(D) √( P²+Q²+2PQcosθ)

Answer: Option D

Question No. 58

A particle moves with a velocity of 2 m/sec in a straight line with a negative acceleration of 0.1 m/sec². Time required to traverse a distance of 1.5 m, is

(A)   40 sec

(B)   30 sec

(C)   20 sec

(D)   15 sec 

Answer: Option C

 

Question No. 59

It is observed that in a certain sinusoidal oscillation, the amplitude is linearly dependent on the frequency f . If the maximum velocity during the oscillation is V , then V must be proportional to

(A)   f

(B)   1/f

(C)   1/f²

(D)   f²

Answer: Option D

 

Question No. 60

One Joule is equivalent to

(A)   9.81 Newton metre

(B)   1 Newton metre

(C)   1 kg wt metre

(D)   1 dyne metre

Answer: Option B

 

Question No. 61

The velocity of a moving body, is

(A)   A vector quantity

(B)   A scalar quantity

(C)   A constant quantity

(D)   None of these 

Answer: Option A

 

Question No. 62

u₁ and u₂ are the velocities of approach of two moving bodies in the same direction and their corresponding velocities of separation are v₁ and v₂ as per Newton's law of collision of elastic bodies, the coefficient of restitution (e) is given by

(A) e = v₁ - v₂/u₂ - u₁

(B) e = u₂ - u₁/v₁ - v₂

(C) e = v₂ - v₁/u₁ - u₂

(D) e = v₁ - v₂/u₂ + u₁

Answer: Option C

Question No. 63

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

(A)   1 sec

(B)   2 sec

(C)   3 sec

(D)   4 sec 

Answer: Option C

 

Question No. 64

A cable loaded with 10 kN/m of span is stretched between supports in the same horizontal line 100 m apart. If the central dip is 10 m, then the maximum and minimum pull in the cable respectively are

(A) 1346.3 kN and 1500 kN

(B) 1436.2 kN and 1250 kN

(C) 1346.3 kN and 1250 kN

(D) 1436.2 kN and 1500 kN 

Answer: Option C

 

Question No. 65

A vehicle weighing w kg is to run on a circular curve of radius r . If the height of its centre of gravity above the road level is h and the distance between the centres of wheels is 2a, the maximum velocity, in order to avoid over turning, will be

(A)   gra/h

(B) √(gra/h)

(C)  ³√(gra/h)

(D)  ⁴√(gra/h)

Answer: Option B

 

Question No. 66

The centre of gravity of a triangle is at the point where three

(A)   Medians of the triangle meet

(B)   Perpendicular bisectors of the sides of the triangle meet

(C)   Bisectors of the angle of the triangle meet

(D)   None of these

Answer: Option A

Question No. 67

For perfectly elastic bodies, the value of coefficient of restitution is

(A) Zero

(B) 0.5

(C) 1.0

(D) Between 0 and 1 

Answer: Option C

 

Question No. 68

A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec²)

(A)   15 m/sec

(B)   25 m/sec

(C)   40 m/sec

(D)   50 m/sec

Answer: Option B

 

Question No. 69

A retarding force on a body does not

(A)   Change the motion of the body

(B)   Retard the motion of the body

(C)   Introduce the motion of the body

(D)   None of these 

Answer: Option B

 

Question No. 70

A cable loaded with 0.5 tonne per horizontal metre span is stretched between supports in the same horizontal line 400 m apart. If central dip is 20 m, the minimum tension in the cable, will be

(A)   200 tonnes at the centre

(B)   500 tonnes at the centre

(C)   200 tonnes at the right support

(D)   200 tonnes at the left support

Answer: Option B

 

Question No. 71

The bending moment in an arch is proportional to

(A)   Vertical ordinate of funicular polygon

(B)   Vertical ordinate of the arch

(C)   Intercept between the arch axis and the funicular polygon

(D)   None of these Answer: Option C

Question No. 72

The C.G. of the shaded area of the below figure from the x-axis is

(A)   a/4

(B)   3a/4

(C) 3b/10

(D) 3a/10 

Answer: Option C

 

Question No. 73

The centre of gravity of a trapezoidal dam section whose top width is a, bottom width is band the vertical side is a, from its vertical face is

(A) (a² + ab + b²)/3 (a + b)

(B) (b² + bc + c²)/3 (b + c)

(C) (a² + ab + c²)/3 (a + c)

(D) None of these 

Answer: Option A

Question No. 74 

Joule is the unit of

(A)   Work

(B)   Force

(C)   Power

(D)   Torque 

Answer: Option A

 

Question No. 75

The equation of motion of a particle starting from rest along a straight line is x = t³ - 3l² + 5. The ratio of the velocities after 5 sec and 3 sec will be

(A)   2

(B)   3

(C)   4

(D)   5

Answer: Option D

 

Question No. 76

If a set of given forces are such that their free vectors build a closed polygon, then

(A)   The resultant force and resultant couple are always zero

(B)   The resultant force is zero but resultant couple is not zero

(C)   The resultant force is zero but resultant couple may not be zero

(D)   The resultant force and resultant couple both may not be zero 

Answer: Option C

 

Question No. 77

To double the period of oscillation of a simple pendulum

(A)   The mass of its bob should be doubled

(B)   The mass of its bob should be quadrupled

(C)   Its length should be quadrupled

(D)   Its length should be doubled 

Answer: Option C

 

Question No. 78

When a body in equilibrium undergoes an infinitely small displacement, work imagined to be done, is known as

(A)   Imaginary work

(B)   Negative work

(C)   Virtual work

(D)   None of these

Answer: Option C

 

Question No. 79

A ball is dropped from a height of 2.25 m on a smooth floor and rises to a height of 1.00 m after the bounce. The coefficient of restitution between the ball and the floor is

(A) 0.33

(B) 0.44

(C) 0.57

(D) 0.67

Answer: Option D

 

Question No. 80

If the resultant of two forces has the same magnitude as either of the force, then the angle between the two forces is

(A) 30°

(B) 45°

(C) 60° 

(D) 120°

Answer: Option D

 

Question No. 81

A ball which is thrown upwards, returns to the ground describing a parabolic path during its flight

(A)   Vertical component of velocity remains constant

(B)   Horizontal component of velocity remains constant

(C)   Speed of the ball remains constant

(D)   Kinetic energy of the ball remains constant

Answer: Option B

 

Question No. 82

A string of length 90 cm is fastened to two points and at the same level 60 cm apart. A ring weighing 120 g is slided on the string. A horizontal force is applied to the ring such that it is in equilibrium vertically below . The value of is:

(A)   40 g

(B)   60 g

(C)   80 g

(D)   100 g

Answer: Option C

 

Question No. 83

A satellite is said to move in a synchronous orbit if it moves at an altitude of 36, 000 km with a maximum velocity of about

(A)   7000 km per hour

(B)   8000 km per hour

(C)   9000 km per hour

(D)   11,000 km per hour 

Answer: Option

 

Question No. 84

A rigid body is in a stable equilibrium if the application of any force

(A)   Can raise the CG of the body but cannot lower it

(B)   Tends to lower the CG of the body

(C)   Neither raises nor lowers the CG of the body

(D)   None of above

Answer: Option A

 

Question No. 85

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

(A)   1.6 t

(B)   9.6 t

(C)   8.5 t

(D)   0.5 t

Answer: Option C

Question No. 86

A uniform rod 9 m long weighing 40 kg is pivoted at a point 2 m from one end where a weight of 120 kg is suspended. The required force acting at the end in a direction perpendicular to rod to keep it equilibrium, at an inclination 60° with horizontal, is

(A)   40 kg

(B)   60 kg

(C)   10 kg

(D)   100 kg

Answer: Option C

 

Question No. 87

The instantaneous centre of a member lies at the point of intersection of two lines drawn at the ends of the member such that the lines are inclined to the direction of motion of the ends at

(A) 30°

(B) 45°

(C) 60°

(D) 90°

Answer: Option D

 

Question No. 88

A flywheel of moment of inertia 20 kgm" is acted upon by a tangential force of 5 N at 2 m from its axis, for 3 seconds. The increase in angular velocity in radian per second is

(A) 1/2

(B) 3/2

(C)   2

(D)   3

Answer: Option B

 

Question No. 89

The phenomenon of collision of two elastic bodies takes place because bodies

(A)   Immediately after collision come momentarily to rest

(B)   Tend to compress each other till they are compressed maximum possible

(C)   Attempt to regain its original shape due to their elasticities

(D)   All the above 

Answer: Option D

 

Question No. 90

The unit of Moment of Inertia of a body, is

(A)   m

(B)   m²

(C)   m³

(D)   m⁴

Answer: Option D

Question No. 91

The angle of friction is:

(A)   The ratio of the friction and the normal reaction

(B)   The force of friction when the body is in motion

(C)   The angle between the normal reaction and the resultant of normal reaction and limiting friction

(D)   The force of friction at which the body is just about to move

Answer: Option C

 

Question No. 92

If a projectile is fired with an initial velocity of 10 m/sec at an angle of 60° to the horizontal, its horizontal and vertical velocity at the highest point of trajectory are

(A)   0 and 5 m/sec

(B)   5 m/sec and 0 

(C)  5√3 m/sec and 0  

(D)  5 and 5√3 m/sec

 Answer: Option B

 

Question No. 93

One Newton force, is

(A)   10³ dynes

(B)   10⁴ dynes

(C)   10⁵ dynes

(D)   10⁶ dynes 

Answer: Option C

 

Question No. 94

A simple pendulum of length l has an energy E , when its amplitude is A . If the length of pendulum is doubled, the energy will be

(A)   E

(B)   E/2

(C)   2E

(D)   4E

Answer: Option B

Question No. 95

A square hole is made in a circular lamina, the diagonal of the square is equal to the radius of the circle as shown in below figure the shift in the centre of gravity 

(A) r(π-0.75)/ (π-0.25)

(B) r(π-0.25)/ (π-0.75)

(C) r(π-0.5)/ (π-0.75)

(D) r(π-0.5)/ (π-0.25)

Answer: Option A

 

Question No. 96

A particle moving with a simple harmonic motion, attains its maximum velocity when it passes

(A)   The extreme point of the oscillation

(B)   Through the mean position

(C)   Through a point at half amplitude

(D)   None of these

Answer: Option B

 

Question No. 97

Pick up the correct statement from the following:

(A)   Nature plays an important role in the launch of a satellite

(B)   The earth's gravity reduces the speed of a satellite by 32 km per second

(C)   The gravitational force relents as the satellite climbs higher

(D)   All the above Answer: Option D

 

Question No. 98

A stone of mass 1 kg is tied to a string of length 1 m and whirled in a horizontal circle at a constant angular speed 5 rad/sec. The tension in the string is,

(A)   5 N

(B)   10 N

(C)   15 N

(D)   25 N

Answer: Option D

Question No. 99

A ladder of weight 'w' rests against a smooth vertical wall, and rests on rough horizontal ground, the coefficient of friction between the ladder and the ground being 1/4. The maximum angle of inclination of the ladder to the vertical, if a man of weight 'w' is to walk to the top of it safely, is tan'1 x, where x is

(A) 1/4

(B) 1/3

(C)   3

(D)   4

Answer: Option B

 

Question No. 100

For a self-locking machine, the efficiency should be

(A) Less than 60%

(B) 50 %

(C)   More than 50%

(D)   None of these

Answer: Option A