The torque required to overcome viscous resistance of a collar bearing is (where R1 andR2 = External and internal radius of collar)
(μπ²N/60t) × (R₁ - R₂)
(μπ²N/60t) × (R₁² - R₂²)
(μπ²N/60t) × (R₁³ - R₂³)
(μπ²N/60t) × (R₁⁴ - R₂⁴)
Correct Answer :
D. (μπ²N/60t) × (R₁⁴ - R₂⁴)
Related Questions
If the atmospheric pressure on the surface of an oil tank (sp. gr. 0.8) is 0.2 kg/cm, the pressure at a depth of 50 m below the oil surface will be
2 meters of water column
3 meters of water column
5 meters of water column
6 meters of water Column
Pitot tube is used for measurement of
Pressure
Flow
Velocity
Discharge
Cavitation is caused by
High velocity
High pressure
Weak material
Low pressure
Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, in the direction of flow of the liquid, is known as
Lift
Drag
Stagnation pressure
Bulk modulus
The flow in a pipe is neither laminar nor turbulent when Reynold number is
Less than 2000
Between 2000 and 2800
More than 2800
None of these
Euler's equation in the differential form for the motion of liquids is given by
dp/ρ + g.dz + v.dv = 0
dp/ρ - g.dz + v.dv = 0
ρ.dp + g.dz + v.dv = 0
ρ.dp - g.dz + v.dv = 0
The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to
2100
2700
10,000
21,000
When the Venturimeter is inclined, then for a given flow it will show __________ reading.
Same
More
Less
None of these
Uniform flow occurs when
The flow is steady
The flow is streamline
Size and shape of the cross section in a particular length remain constant
Size and cross section change uniformly along length
The discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.
Less than
More than
Equal to
None of these
A flow whose streamline is represented by a curve, is called
One-dimensional flow
Two-dimensional flow
Three-dimensional flow
Four-dimensional flow
Reynold's number is the ratio of the inertia force to the
Surface tension force
Viscous force
Gravity force
Elastic force
Rain drops are spherical because of
Viscosity
Air resistance
Surface tension forces
Atmospheric pressure
The most efficient section of a channel is
Triangular
Rectangular
Square
Trapezoidal
The velocity at which the flow changes from laminar flow to turbulent flow is called
Critical velocity
Velocity of approach
Sub-sonic velocity
Super-sonic velocity
The specific weight of water is 1000 kg/m3
At normal pressure of 760 mm
At 4°C temperature
At mean sea level
All the above
In a broad-crested weir, the discharge is maximum if the head of water on the downstream side of weir is __________ the head of water on the upstream side of weir.
Equal to
One-third
Two-third
Three-fourth
The fluid forces considered in the Navier Stokes equation are
Gravity, pressure and viscous
Gravity, pressure and turbulent
Pressure, viscous and turbulent
Gravity, viscous and turbulent
The units of kinematic viscosity are
Metres² per sec
kg sec/metre
Newton-sec per metre
Newton-sec per metre
A flow through a long pipe at constant rate is called
Steady uniform flow
Steady non-uniform flow
Unsteady uniform flow
Unsteady non-uniform flow
The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.
0.34 times
0.67 times
0.81 times
0.95 times
The specific weight of water in S.I. units is taken as
9.81 kN/m3
9.81 × 103 N/m3
9.81 × 10-6 N/mm3
Any one of these
The specific gravity of water is taken as
0.001
0.01
0.1
1
The meatcentric height of a ship is 0.6 m and the radius of gyration is 4 m. The time of rolling of a ship is
4.1 s
5.2 s
10.4 s
14.1 s
For manometer, a better liquid combination is one having
Higher surface tension
Lower surface tension
Surface tension is no criterion
High density and viscosity
According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
The weight of the body
More than the weight of the body
Less than the weight of the body
Weight of the fluid displaced by the body
The celerity (velocity) of a pressure wave in a fluid is given by (where K = Bulk modulus, and ρ = Density of the fluid)
K.ρ
K/ρ
ρ/K
None of these
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Law of gravitation
Archimedes principle
Principle of buoyancy
All of the above
When a body is immersed wholly or partially in a liquid, it is lifted up by a force equal to the weight of liquid displaced by the body. This statement is called
Pascal's law
Archimedess principle
Principle of floatation
Bernoulli's theorem
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Sub-sonic flow
Sonic flow
Super-sonic flow
Hyper-sonic flow