The length of a Second's pendulum, is
99.0 cm
99.4 cm
100 cm
101 cm
Correct Answer :
B. 99.4 cm
Related Questions
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
0.33
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
gra/h
√(gra/h)
3√(gra/h)
4√(gra/h)
If the angular distance, 0 = 2t3 - 3t², the angular acceleration at t = 1 sec. is
1 rad/sec²
4 rad/sec²
6 rad/sec²
12 rad/sec²
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
A string of length 90 cm is fastened to two points A and B at the same level 60 cm apart. A ring weighing 120 g is slided on the string. A horizontal force P is applied to the ring such that it is in equilibrium vertically below B. The value of P is:
40 g
60 g
80 g
100 g
The condition of equilibrium for any system of forces in a plane is
That polygon of forces must close
That resultant couple must be zero
Both (A) and (B)
None of the above
M.I. of a thin ring (external diameter D, internal diameter d) about an axis perpendicular to the plane of the ring, is
π/64 (D4 + d4)
π/32 (D4 - d4)
π/32 (D4 + d4)
π/32 (D4 × d4)
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
Original velocity in the same direction
Half the original velocity in the same direction
Half the original velocity in the opposite direction
Original velocity in the opposite direction
According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centres lie on
A point
A straight line
Two straight lines
A triangle
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)
15 m/sec
25 m/sec
40 m/sec
50 m/sec
The maximum pull in a cable, carrying a uniformly distributed load and supported at two ends which are at the same level, is at
Supports
Quarter span
Mid span
None of the above
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 force acting on a point on the surface of a rigid body may be considered to act
At the centre of gravity of the body
On the periphery of the body
On any point on the line of action of the force
At any point on the surface normal to the line of action of the force
The units of inertia of mass are
kg/m
kg/m2
m4
kg-m2
A spring scale in a stationary lift shows a reading of 60 kg for a man standing on it. If the lift starts descending at an acceleration of g/5, the scale reading would be
48 kg
60 kg
72 kg
None of these
The moment of inertia of a triangular section (base b, height h) about centroidal axis parallel to the base, is
b3h/12
bh3/3
bh3/36
bh3/2
In the structure shown in below figure, the member which carries zero force, is 
AB
BC
BE
All the above
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
1.5 m
For a simple pendulum, time period for a beat, is
π √(l/g)
π √(2l/g)
π √(g/2l)
π √(l/2g)
Minimum potential energy of a system will be in the position of
Stable equilibrium
Unstable equilibrium
Neutral equilibrium
All of the above
A marble ball is rolled on a smooth floor of a room to hit a wall. If the time taken by the ball in returning to the point of projection is twice the time taken in reaching the wall, the coefficient of restitution between the ball and the wall, is
0.25
0.50
0.75
1.0
A system of coplanar forces acting on a rigid body can be reduced to
One force only
One couple only
One force and one couple only
None of the above
The condition for a lifting machine to be reversible is that its efficiency should be
Less than 50%
More than 50%
More than 66.67%
Equal to 100%
The velocity ratio of an inclined plane of inclination θ with horizontal for lifting a load is
sin θ
cos θ
tan θ
cosec θ
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 velocity ratio of the lifting machine is
50
55
60
65
A stone is thrown up a slope of inclination 60° to the horizontal. At what angle to the slope must the stone be thrown so as to land as far as possible from the point of projection?
15°
30°
45°
75°
Time of flight of a projectile on a horizontal plane, is
2u sinα/g
2u cosα/g
2u tanα/g
2u cotα/g
A satellite goes on moving along its orbit round the earth due to
Gravitational force
Centrifugal force
Centripetal force
None of these
The horizontal reaction at the support A of the structure shown in below figure, is
Zero
2 t
3 t
1 t
The reaction at the support D of the continuous beam ABCD, hinged at two points shown in below figure is 
1.6 t
1.6 t ↓
0.5 t
0.5 t ↓