A trolley wire weighs 1 kg per metre length. The ends of the wire are attached to two poles 20 m apart. If the horizontal tension is 1000 kg, the central dip of the cable is
2 cm
3 cm
4 cm
5 cm
Correct Answer :
D. 5 cm
Related Questions
At the instantaneous center, the velocity of the moving lamina at any instant is
Zero
Maximum
Minimum
Varying
A projectile is thrown at an angle α to the horizontal with velocity v. It will have the maximum centripetal acceleration
At the start
At the top of the trajectory
As it strikes the ground
Elsewhere
The height at which the end of a rope of length l should be tied so that a man pulling at the other end may have the greatest tendency to overturn the pillar, is
¾ l
½ l
l/√2
2/√3 l
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An acceleration
Linear momentum
Retardation
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?
Disc with larger density
Disc with smaller density
Both discs will have same rotational inertia
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A particle is dropped from a height of 3 m on a horizontal floor, which has a coefficient of restitution with the ball of 1/2. The height to which the ball will rebound after striking the floor is
0.5 m
0.75 m
1.0 m
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The total time of collision and restitution of two bodies, is called
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Period of collision
Period of impact
All the above
If a ball which is dropped from a height of 2.25 m on a smooth floor attains the height of bounce equal to 1.00 m, the coefficient of the restitution between the ball and floor, is
0.25
0.50
0.67
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The resultant of two forces acting at right angles is √34 kg and acting at 60° is 70 kg. The forces are
1 kg and 4 kg
2 kg and 3 kg
√3 kg and √5 kg
3 kg and 5 kg
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)
Joule is the unit of
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Force
Power
Torque
The moment of inertia of the shaded portion of the area shown in below figure about the X-axis, is
229.34 cm4
329.34 cm4
429.34 cm4
529.34 cm4
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Oscillation
Beat
Amplitude
The direction of projection should bisect the angle between the inclined plane and the vertical for a range of a projectile on inclined plane
To be zero
To be maximum
To be minimum
None of these
Two balls of masses 3 kg and 6 kg are moving with velocities of 4 m/sec and 1 m/sec respectively, towards each other along the line of their centers. After impact the 3 kg ball comes to rest. This can happen only if the coefficient of restitution between the balls is
2/3
1/5
3/5
1/3
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
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More than 50%
More than 66.67%
Equal to 100%
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Concurrent
Parallel
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None of these
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Cannot be obtained by graphic statics
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Can be obtained by graphic statics by trial and error
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Rotate about itself without moving
Move in any one direction
Move in any one direction rotating about itself
All the above
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Triangle
Open polygon
Closed polygon
Parallelogram
Pick up the correct statement from the following. A rubber ball when strikes a wall rebounds but a lead ball of same mass and velocity when strikes the same wall, falls down
Rubber and lead balls undergo equal changes in momentum
Change in momentum suffered by lead ball is less that of rubber ball
Momentum of rubber ball is less than that of lead ball
None of these
A body A of mass 6.6 kg which is lying on a horizontal platform 4.5 m from its edge is connected to the end of a light string whose other end is supporting a body of mass 3.2 kg as shown in below figure. If the friction between the platform and the body A is 1/3, the acceleration is 
0.5 m/sec2
0.75 m/sec2
1.00 m/sec2
1.25 m/sec2
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h/3
h/4
2h/3
3h/4
A train weighing 196 tonnes experiences a frictional resistance of 5 11/22 per tonne. The speed of the train at the top of a down gradient 1 in 78.4 is 36 km/hour. The speed of the train after running 1 km down the slope, is
5 √10 m/sec
10 √5 m/sec
5 √3 m/sec
3 √5 m/sec
The necessary condition of equilibrium of a body is:
Algebraic sum of horizontal components of all the forces must be zero
Algebraic sum of vertical components of all the forces must be zero
Algebraic sum of the moments of the forces about a point must be zero
All (a), (b) and (c)
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
On a ladder resisting on a smooth ground and leaning against a rough vertical wall, the force of friction acts
Towards the wall at its upper end
Away from the wall at its upper end
Upwards at its upper end
Downwards at its upper end
The centre of gravity of a homogenous body is the point at which the whole
Volume of the body is assumed to be concentrated
Area of the surface of the body is assumed to be concentrated
Weight of the body is assumed to be concentrated
All the above
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A variable acceleration
A variable retardation