Terms (Fluid Mechanics and Hydraulics) Flashcards
Liquids
a. cannot be compressed
b. do not occupy definite shape
c. are not affected by change in pressure and temperature
d. none of these
b. do not occupy definite shape
Specific weight of liquids
a. remains constant at every place.
b. does not remain constant at every place.
c. varies from place to place on the earth.
d. does not vary on any other planet.
d. does not vary on any other planet.
The specific weight of water is 1000 kg/m3
a. at normal pressure of 760 mm
b. at 4 deg C temperature
c. at mean sea level
d. all of the above
d. all of the above
Specific weight of sea water is more than that of pure water because of
a. dissolved air
b. dissolved salts
c. suspended matter
d. all of the above
d. all of the above
Water belongs to
a. Newtonian fluids
b. Non-Newtonian fluids
c. Compressible Fluids
d. None of these
a. Newtonian fluids
Fluids change the volume under external pressure due to
a. plasticity
b. viscosity
c. compressibility
d. none of these
c. compressibility
Molecules of fluids get attracted due to
a. capillary rise
b. surface tension
c. adhesion
d. cohesion
c. adhesion
Falling drops of water become spheres due to
a. adhesion
b. cohesion
c. surface tension
d. capillary rise
c. surface tension
In an open tube, free surface of mercury remains
a. horizontal
b. curved upwards
c. curved downwards
d. none of these
c. curved downwards
If cohesion between the molecules of a fluid is more than adhesion between the fluid and glass, the free level of fluid in a dipped glass tube will be
a. higher than the surface of liquid
b. same as the surface of liquid
c. lower than the surface of liquid
d. none of these
c. lower than the surface of liquid
A rise or fall of liquid in a glass tube of a very small diameter when dipped is
a. directly proportional to the force per unit length of periphery
b. directly proportional to the sine of the angle of contact
c. directly proportional to the specific weight of liquid
d. inversely proportional to the diameter of the glass tube
c. directly proportional to the specific weight of liquid
Hydrostatic pressure on dam depends upon its
a. length
b. depth
c. shape
d. both (b) and (c)
d. both (b) and (c)
Barometers are used to measure
a. pressure in water channels, pipes, etc.
b. difference in pressure at two points
c. atmospheric pressure
d. very low pressure
c. atmospheric pressure
Piezometers are used to measure
a. pressure in water channels, pipes, etc.
b. difference in pressure at two points
c. atmospheric pressure
d. very low pressure
d. very low pressure
Manometers are used to measure
a. pressure in water channels, pipes, etc.
b. difference in pressure at two points
c. atmospheric pressure
d. very low pressure
a. pressure in water channels, pipes, etc.
Differential manometers are used to measure
a. pressure in water channels, pipes, etc.
b. difference in pressure at two points
c. atmospheric pressure
d. very low pressure
b. difference in pressure at two points
The pressure less than atmospheric pressure is known
a. suction pressure
b. vacuum pressure
c. negative gauge pressure
d. all of the above
d. all of the above
Atmospheric pressure varies with
a. altitude
b. temperature
c. weather conditions
d. none of these
d. none of these
Mercury is generally used in barometers because
a. its vapor pressure is practically zero
b. the height of barometer will be less
c. it is a best liquid
d. both (a) and (b)
d. both (a) and (b)
The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at its centroid if
a. area is horizontal
b. area is vertical
c. area is inclined
d. all of the above
d. all of the above
The center of pressure of a vertical plane immersed in a liquid is at
a. center of higher edge
b. center of lower edge
c. centroid of the area
d. none of these
d. none of these
On an inclined plane, center of pressure is located
a. at the centroid
b. above the centroid
c. below the centroid
d. anywhere
c. below the centroid
When a body is totally or partially immersed in a fluid, it is buoyed up by a force equal to
a. weight of the body
b. weight of the fluid displaced by the body
c. weight of the body and fluid displaced by the body
d. difference of weights of the fluid displaced and that of the body
b. weight of the fluid displaced by the body
A floating body attains stable equilibrium if its metacenter is
a. at the centroid
b. above the centroid
c. below the centroid
d. anywhere
b. above the centroid
Center of buoyancy is
a. center of the floating body
b. centroid of the fluid displaced
c. center pressure of the displaced liquid
d. none of these
b. centroid of the fluid displaced
The rise of the liquid along the walls of a revolving cylinder above the initial level
a. greater than the depression of the liquid
b. lesser than the depression of the liquid at the axis of rotation
c. the same as the depression of the liquid at the axis of rotation
d. none of these
c. the same as the depression of the liquid at the axis of rotation
When a liquid rotates at constant angular velocity about a vertical axis of a rigid body, the pressure
a. increases linearly to its radial distance
b. varies inversely as the altitude along any vertical line
c. varies as the square of the radial distance
d. decreases as the square of the radial distance
c. varies as the square of the radial distance
The imaginary line drawn such that the tangents at its all points indicate the direction of the velocity of the fluid particles at each point is called
a. path line
b. stream line
c. potential line
d. streak line
b. stream line