The unit of energy in S.I. units is
Dyne
Watt
kg-m
Joule
Correct Answer :
D. Joule
Related Questions
The time of flight of a projectile on downward inclined plane depends upon
Angle of projection
Angle of inclination of the plane
Both (A) and (B)
None of these
The unit of force in S.I. units is
kilogram
Newton
Watt
Dyne
In order to double the period of simple pendulum, the length of the string should be
Halved
Doubled
Quadrupled
None of these
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
One joule means that
Work is done by a force of 1 N when it displaces a body through 1 m
Work is done by a force of 1 kg when it displaces a body through 1 m
Work is done by a force of 1 dyne when it displaces a body through 1 cm
Work is done by a force of 1 g when it displaces a body through 1 cm
A pendulum which executes one beat per second is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
A spherical body is symmetrical about its perpendicular axis. According to Routh's rule, the moment of inertia of a body about an axis passing through its centre of gravity is (where, M = Mass of the body, and S = Sum of the squares of the two semi-axes.)
MS/3
MS/4
MS/5
None of these
Moment of inertia of a hollow rectangular section as shown in the below figure about X-X axis, is 
(BD³/12) - (bd³/12)
(DB³/12) - (db³/12)
(BD³/36) - (bd³/36)
(DB³/36) - (db³/36)
The C.G. of a right circular solid cone of height h lies at the following distance from the base
h/2
J/3
h/6
h/4
A pair of smith's tongs is an example of the lever of
Zeroth order
First order
Second order
Third order
On a ladder resting on smooth ground and leaning against vertical wall, the force of friction will be
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
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
According to parallel axis theorem, the moment of inertia of a section about an axis parallel to the axis through centre of gravity (i.e. IP) is given by(where, A = Area of the section, IG = Moment of inertia of the section about an axis passing through its C.G., and h = Distance between C.G. and the parallel axis.)
IP = IG + Ah2
IP = IG - Ah2
IP = IG / Ah2
IP = Ah2 / IG
The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as
Principle of independence of forces
Principle of resolution of forces
Principle of transmissibility of forces
None of these
The maximum height of a projectile on a horizontal plane, is
u² sin²α/2g
u² cos²α/2g
u² sin²α/g
u² cos²α/g
A body of weight W is required to move up on rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tanφ = Coefficient of friction between the plane and the body.)
P = W tanα
P = W tan (α + φ)
P = W (sinα + μcosα)
P = W (cosα + μsinα)
Moment of inertia of a hollow circular section, as shown in the below figure about an axis perpendicular to the section, is __________ than that about X-X axis. 
Two times
Same
Half
None of these
Efficiency of a screw jack is given by (where α = Helix angle, and φ = Angle of friction.)
tan(α + φ)/tanα
tanα/tan (α + φ)
tan(α - φ)/tanα
None of these
The unit of force in S.I. system of units is
Dyne
Kilogram
Newton
Watt
In order to completely specify angular displacement by a vector, it must fix
Direction of the axis of rotation
Magnitude of angular displacement
Sense of angular displacement
All of these
The loss of kinetic energy during inelastic impact, is given by (where m1 = Mass of the first body, m2 = Mass of the second body, and u1 and u2 = Velocities of the first and second bodies respectively.)
[m₁ m₂/2(m₁ + m₂)] (u₁ - u₂)²
[2(m₁ + m₂)/m₁ m₂] (u₁ - u₂)²
[m₁ m₂/2(m₁ + m₂)] (u₁² - u₂²)
[2(m₁ + m₂)/m₁ m₂] (u₁² - u₂²)
A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if
The floor is smooth, the wall is rough
The floor is rough, the wall is smooth
The floor and wall both are smooth surfaces
The floor and wall both are rough surfaces
According to the law of moments, if a number of coplanar forces acting on a particle are in equilibrium, then
Their algebraic sum is zero
Their lines of action are at equal distances
The algebraic sum of their moments about any point in their plane is zero
The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.
The force applied on a body of mass 100 kg to produce an acceleration of 5 m/s2, is
20 N
100 N
500 N
None of these
The moment of inertia of a square of side (a) about an axis through its centre of gravity is
a4/4
a4/8
a4/12
a4/36
If a suspended body is struck at the centre of percussion, then the pressure on die axis passing through the point of suspension will be
Maximum
Minimum
Zero
Infinity
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
If two bodies having masses m1 and m2 (m1>m2) have equal kinetic energies, the momentum of body having mass m1 is _________ the momentum of body having mass m2.
Equal to
Less than
Greater than
None of these
Which of the following do not have identical dimensions?
Momentum and impulse
Torque and energy
Torque and work
Moment of a force and angular momentum.
If a number of forces are acting at a point, their resultant will be inclined at an angle θ with the horizontal, such that
tanθ = ΣH/ΣV
tanθ = ΣV/ΣH
tanθ = ΣV × ΣH
tanθ = √(ΣV + ΣH)