The length of a second's pendulum is
94.9 cm
99.4 cm
100 cm
101 cm
Correct Answer :
B. 99.4 cm
Related Questions
If the gravitational acceleration at any place is doubled, then the weight of a body will be
g/2
g
√2.g
2g
A single force and a couple acting in the same plane upon a rigid body
Balance each other
Cannot balance each other
Produce moment of a couple
Are equivalent
The unit of force in S.I. units is
kilogram
Newton
Watt
Dyne
Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, is
bh3/4
bh3/8
bh3/12
bh3/36
A machine having an efficiency less than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
The resolved part of the resultant of two forces inclined at an angle θ in a given direction is equal to
The algebraic sum of the resolved parts of the forces in the given direction
The sum of the resolved parts of the forces in the given direction
The difference of the forces multiplied by the cosine of θ
The sum of the forces multiplied by the sine of θ
A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
5
10
20
40
Mass moment of inertia of a uniform thin rod of mass M and length (l) about its mid-point and perpendicular to its length is
(2/3) Ml2
(1/3) Ml2
(3/4) Ml2
(1/12) Ml2
Static friction is always __________ dynamic friction.
Equal to
Less than
Greater than
None of these
A smooth cylinder lying on a __________ is in neutral equilibrium.
Curved surface
Convex surface
Horizontal surface
None of these
The force induced in the string AB due to the load W, as shown in the below figure is 
W sinθ
W cosθ
W secθ
W cosecθ
When a body of mass moment of inertia I (about a given axis) is rotated about that axis with an angular velocity to, then the kinetic energy of rotation is
Iω
Iω2
0.5 Iω
0.5 Iω2
The unit of work or energy in S.I. units is
Newton
Pascal
Watt
Joule
A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly
38 m
62.5 m
96 m
124 m
Which of the following is an equation of linear motion? (where, u and v = Initial and final velocity of the body, a = Acceleration of the body, and s = Displacement of the body in time t seconds.)
v = u + a.t
s = u.t + ½ a.t2
v2 = u2 + 2a.s
All of these
In the equation of virtual work, following force is neglected
Reaction of any smooth surface with which the body is in contact
Reaction of a rough surface of a body which rolls on it without slipping
Reaction at a point or an axis, fixed in space, around which a body is constrained to turn
All of the above
The friction experienced by a body, when in motion, is known as
Rolling friction
Dynamic friction
Limiting friction
Static friction
The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction.)
α = 45° + φ/2
α = 45° - φ/2
α = 90° + φ
α = 90° - φ
Which of the following statement is correct?
The algebraic sum of the forces, constituting the couple is zero
The algebraic sum of the forces, constituting the couple, about any point is the same
A couple cannot be balanced by a single force but can be balanced only by a couple of opposite sense
All of the above
In a screw jack, the effort required to lift the load is given by (where W = Load lifted, α = Helix angle, and φ = Angle of friction.)
P = W tan (α - φ)
P = W tan (α + φ)
P = W tan (φ - α)
P = W cos (α + φ)
The moment of a force
Is the turning effect produced by a force, on the body, on which it acts
Is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force
Is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the moment is taken
All of the above
The wheels of a moving car possess
Potential energy only
Kinetic energy of translation only
Kinetic energy of rotation only
Kinetic energy of translation and rotation both
The total momentum of a system of masses (i. e. moving bodies) in any one direction remains constant, unless acted upon by an external force in that direction. This statement is called
Newton's first law of motion
Newton's second law of motion
Principle of conservation of energy
Principle of conservation of momentum
A pendulum which executes one beat per second is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
2.5 cm
3.0 cm
4.0 cm
5.0 cm
The unit of power in S.I. units is
Horsepower
Joule
Watt
kg-m
If n = number of members and y = number of joints, then for a perfect frame, n = ?
1/2
2/3
3/2
2/4
The C.G. of a solid hemisphere lies on the central radius 3r
At distance from the plane base 3r
At distance from the plane base 3r
At distance from the plane base 3r
At distance from the plane base
The velocity ratio in case of an inclined plane inclined at angle θ to the horizontal and weight being pulled up the inclined plane by vertical effort is
sinθ
cosθ
tanθ
cosecθ
In ideal machines
Mechanical advantage is greater than velocity ratio
Mechanical advantage is equal to velocity ratio
Mechanical advantage is less than velocity ratio
Mechanical advantage is unity