Ratio of inertia force to elastic force is known as
Mach number
Froude number
Reynolds number
Weber's number
Correct Answer :
A. Mach number
Related Questions
Surface tension has the units of
Newton-sec/m
Newton-m/sec
Newton/m
Newton
The velocity corresponding to Reynold number of 2000 is called
Sub-sonic velocity
Super-sonic velocity
Lower critical velocity
Higher critical velocity
If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be
Higher than the surface of liquid
The same as the surface of liquid
Lower than the surface of liquid
Unpredictable
Bernoulli's equation is applied to
Venturimeter
Orifice meter
Pitot tube
All of these
Metacentric height is given as the distance between
The center of gravity of the body and the metacentre
The center of gravity of the body and the center of buoyancy
The center of gravity of the body and the center of pressure
Center of buoyancy and metacentre
In an isothermal atmosphere, the pressure
Decreases linearly with elevation
Remain constant
Varies in the same way as the density
Increases exponentially with elevation
The units of kinematic viscosity are
Metres² per sec
kg sec/metre
Newton-sec per metre
Newton-sec per metre
The siphon will work satisfactorily, if the minimum pressure in the pipe is __________ vapour pressure of liquid.
Equal to
Less than
More than
None of these
The pressure of a liquid measured with the help of a Piezometer tube is
Vacuum pressure
Gauge pressure
Absolute pressure
Atmospheric pressure
The velocity corresponding to Reynold number of 2800, is called
Sub-sonic velocity
Super-sonic velocity
Lower critical velocity
Higher critical velocity
A flow in which the quantity of liquid flowing per second is constant, is called __________ flow.
Steady
Streamline
Turbulent
Unsteady
Coefficient of resistance is the ratio of
Actual velocity of jet at vena-contracta to the theoretical velocity
Area of jet at vena-contracta to the area of orifice
Loss of head in the orifice to the head of water available at the exit of the orifice
Actual discharge through an orifice to the theoretical discharge
When a liquid is flowing through a pipe, the velocity of the liquid is
Maximum at the centre and minimum near the walls
Minimum at the centre and maximum near the walls
Zero at the centre and maximum near the walls
Maximum at the centre and zero near the walls
Mercury is often used in barometer because
It is the best liquid
The height of barometer will be less
Its vapour pressure is so low that it may be neglected
Both (B) and (C)
A liquid would wet the solid, if adhesion forces as compared to cohesion forces are
Less
More
Equal
Less at low temperature and more at high temperature
The units of dynamic or absolute viscosity are
Metres² per sec
kg sec/meter
Newton-sec per meter
Newton-sec² per meter
Flow occurring in a pipeline when a valve is being opened is
Steady
Unsteady
Laminar
Vortex
The buoyancy depends on
Mass of liquid displaced
Viscosity of the liquid
Pressure of the liquid displaced
Depth of immersion
The force per unit length is the unit of
Surface tension
Compressibility
Capillarity
Viscosity
The conditions for the stable equilibrium of a floating body are
The metacentre should lie above the center of gravity
The center of buoyancy and the center of gravity must lie on the same vertical line
A righting couple should be formed
All the above are correct
The discharge 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 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 diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcys coefficient of friction for pipe, and l = Length of pipe)
d = (D⁵/8fl)1/2
d = (D⁵/8fl)1/3
d = (D⁵/8fl)1/4
d = (D⁵/8fl)1/5
The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
Half the depth
Half the breadth
Twice the depth
Twice the breadth
The upper surface of a weir over which water flows is known is
Crest
Nappy
Sill
Weir top
Rotameter is a device used to measure
Absolute pressure
Velocity of fluid
Flow
Rotation
The discharge through a large rectangular orifice is given by (where H1 = Height of the liquid above the top of the orifice, H2 = Height of the liquid above the bottom of the orifice, b = Breadth of the orifice, and Cd = Coefficient of discharge)
Q = (2/3) Cd × b × √(2g) × (H2 - H1)
Q = (2/3) Cd × b × √(2g) × (H2 1/2 - H1 1/2)
Q = (2/3) Cd × b × √(2g) × (H2 3/2 - H1 3/2)
Q = (2/3) Cd × b × √(2g) × (H2 2 - H1 2)
Choose the wrong statement
Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force
Viscosity is due primarily to interaction between fluid molecules
Viscosity of liquids decreases with increase in temperature
Viscosity of liquids is appreciably affected by change in pressure
Which of the following is dimensionless?
Specific weight
Specific volume
Specific speed
Specific gravity
The water pressure per metre length on a vertical masonry wall of dam is (where w = Specific weight of the liquid, and H = Height of the liquid)
wH/2
wH
wH2/2
wH2/4