Total no of instantaneous centres of a machine having n links, is
n/2
n
(n - 1)
n (n - 1)/2
Correct Answer :
D. n (n - 1)/2
Related Questions
In a lifting machine a weight of 5 kN is lifted through 200 mm by an effort of 0.1 kN moving through 15 m. The mechanical advantage and velocity ratio of the machine are respectively
50 and 75
75 and 50
75 and 75
50 and 50
A particle moves along a straight line such that distance x traversed in t seconds is given by x = t2(t + 1), the acceleration of the particle, will be
3t3 - 2t
3t2 + 2t
6t - 2
6t + 2
The reaction RB of the roller support B of the beam shown in below figure is 
10.8 t
10.6 t
10.4 t
10.2 t
A 2 m long ladder rests against a wall and makes an angle of 30° with the horizontal floor. Where will be the instantaneous center of rotation when the ladder starts slipping? (i) 1.0 in from the wall (ii) 1.732 m from the wall (iii) 1.0 m above the floor (iv) 1.732 m above the floor The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
A geo-stationary satellite is one which orbits the earth with a velocity of rotation of
Moon
Earth
Sun
Pole
A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The efficiency of the lifting machine is
50 %
40 %
55 %
30 %
The following statement is one of the laws of Dynamic friction
The force of friction always acts in a direction opposite to that in which a body is moving
The magnitude of the kinetic friction bears a constant ratio to the normal reaction between two surfaces. The ratio being slightly less than that in the case of limiting friction
For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed
All the above
The unit of moments in M.K.S system, is
kg.m
kg/m2
kg/sec2
kg/sec
The shape of a suspended cable for a uniformly distributed load over it is
Circular
Parabolic
Catenary
Cubic parabola
On a ladder resting on a rough ground and leaning against a smooth vertical wall, the force of friction acts
Downwards at its upper end
Upwards at its upper end
Perpendicular to the wall at its upper end
Zero at its upper end
Impulse can be obtained from a
Force-displacement diagram
Force-time diagram
Velocity-time diagram
Velocity-displacement diagram
The shape of a suspended cable under its own weight, is
Parabolic
Circular
Catenary
Elliptical
The maximum frictional force which comes into play, when a body just begins to slide over the surface of a another body, is known
Sliding friction
Rolling friction
Limiting friction
None of these
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
0 and 5 m/sec
5 m/sec and 0
5√3 m/sec and 0
5 and 5√3 m/sec
For a body moving with simple harmonic motion, the number of cycles per second, is known as its
Oscillation
Amplitude
Periodic time
Frequency
The velocity ratio of the differential wheel and axle is
R/r1 - r2
2R/r1
3R/r1 - r2
2R/r1 + r2
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
1.00 m/sec
1.57 m/sec
3.14 m/sec
6.28 m/sec
Pick up the correct statement from the following:
Nature plays an important role in the launch of a satellite
The earth's gravity reduces the speed of a satellite by 32 km per second
The gravitational force relents as the satellite climbs higher
All the above
The angular speed of a car taking a circular turn of radius 100 m at 36 km/hr will be
0.1 rad/sec
1 rad/sec
10 rad/sec
100 rad/sec
One Newton is equivalent to
105 dyne
106 dyne
107 dyne
108 dyne
Moment of inertia of a squares of side b about an axis through its centre of gravity, is
b3/4
b4/12
b4/3
b4/8
A body is dropped from a height of 100 m and at the same time another body is projected vertically upward with a velocity of 10 m/sec. The two particles will
Never meet
Meet after 1 sec
Meet after 5 sec
Meet after 10 sec
A square hole is punched out of a circular lamina, the diagonal of the square being the radius of the circle. If r is the radius of the circle, the C.G. of the remainder from the corner of the square on the circumference will be
[r (π + 0.25)]/(π - 0.5)
[r (π - 0.5)]/(π + 0.25)
[r (π - 0.25)]/(π - 0.5)
[r (π + 0.25)]/(π + 0.5)
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
60 N
80 N
100 N
120 N
For lifting a load of 50 kg through a distance of 2.5 cm, an effort of 12.5 kg is moved through a distance of 40 cm. The efficiency of the lifting machine, is
60 %
65 %
70 %
75 %
Time required to stop a car moving with a velocity 20 m/sec within a distance of 40 m, is
2 sec
3 sec
4 sec
5 sec
From a solid cylinder of height 8 cm and radius 4 cm, a right circular cone is scooped out on the same base and having the same height as that of the cylinder. The C.G. of the remainder is at a height of
4.5 cm
5.0 cm
5.25 cm
5.5 cm
A ball which is thrown upwards, returns to the ground describing a parabolic path during its flight
Vertical component of velocity remains constant
Horizontal component of velocity remains constant
Speed of the ball remains constant
Kinetic energy of the ball remains constant
An ordinate in a funicular polygon represents
Shear force
Resultant force
Bending moment
Equilibrium
The unit of impulse, is
kg.m/sec
kg.m/sec
kg.m/sec2
kg.m/sec