A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
Density of metal can't be determined
Metal is twice as dense as water
Metal will float in water
Metal is twice as dense as unknown fluid
Correct Answer :
A. Density of metal can't be determined
Related Questions
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 unit of work or energy in S.I. units is
Newton
Pascal
Watt
Joule
Limiting force of friction is the
Tangent of angle between normal reaction and the resultant of normal reaction and limiting friction
Ratio of limiting friction and normal reaction
The friction force acting when the body is just about to move
The friction force acting when the body is in motion
The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
Friction
Limiting friction
Repose
Kinematic friction
Tension in the cable supporting a lift is more when the lift is moving __________ with an acceleration.
Upwards
Downwards
Horizontal
None of these
Moment of inertia of a rectangular section having width (b) and depth (d) about an axis passing through its C.G. and parallel to the width (b), is
db³/12
bd³/12
db³/36
bd³/36
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 velocity ratio of a first system of pulleys with 4 pulleys is
4
8
16
20
The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction in which the force acts. This statement is known as
Newton's first law of motion
Newton's second law of motion
Newton's third law of motion
None of these
If the masses of both the bodies, as shown in the below figure, are doubled, then the acceleration in the string will be 
Same
Half
Double
None of these
The periodic time (T) is given by (where, ω = Angular velocity of particle in rad/s.)
ω/2π
2π/ω
2π × ω
π/ω
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
The amplitude is always __________ radius of the circle.
Equal to
Less than
Greater than
None of these
The velocity ratio for the third system of pulleys is
n
n²
2n
2n - 1
For a self locking machine, the efficiency must be
Equal to 50 %
Less than 50 %
Greater than 50 %
100 %
The length of a second's pendulum is
94.9 cm
99.4 cm
100 cm
101 cm
Which of the following is a vector quantity?
Energy
Mass
Momentum
Angle
The forces, which meet at one point and their lines of action also lie on the same plane, are known as
Coplanar concurrent forces
Coplanar non-concurrent forces
Non-coplanar concurrent forces
Non-coplanar non-concurrent forces
A ladder is resting on a rough ground and leaning against a smooth vertical wall. The force of friction will act
Downward at its upper end
Upward at its upper end
Zero at its upper end
Perpendicular to the wall at its upper end
A number of forces acting at a point will be in equilibrium, if
All the forces are equally inclined
Sum of all the forces is zero
Sum of resolved parts in the vertical direction is zero (i.e. ΣV = 0)
None of these
If u1 and u2 are the velocities of two moving bodies in the same direction before impact and v1 and v2 are their velocities after impact, then coefficient of restitution is given by
(v1 - v2)/(u1 - u2)
(v₂ - v₁)/(u1 - u2)
(u1 - u2)/(v1 - v2)
(u₂ + u₁)/(v₂ + v₁)
A body will begin to move down an inclined plane if the angle of inclination of the plane is _________ the angle of friction.
Equal to
Less than
Greater than
None of these
Which of the following is not a scalar quantity?
Mass
Volume
Density
Acceleration
The coefficient of restitution for inelastic bodies is
Zero
One
Between zero and one
More than one
The moment of inertia of a sphere of mass m and radius r, about an axis tangential to it, is
2mr2/3
2mr2/5
7mr2/3
7mr2/5
The process of finding out the resultant force is called __________ of forces.
Composition
Resolution
Decomposition
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.
The maximum acceleration of a particle moving with simple harmonic motion is
ω
ωr
ω2r
ω/r
Which of the following statement is incorrect?
A force acting in the opposite direction to the motion of the body is called force of friction
The ratio of the limiting friction to the normal reaction is called coefficient of friction
A machine whose efficiency is 100% is known as an ideal machine
The velocity ratio of a machine is the ratio of load lifted to the effort applied
The units of moment of inertia of an area are
kg-m²
m⁴
kg/m²
m³