Question

For (8) questions only, choose the correct answer
1. The variations in pressure and temperature generally have only a small effect on liquid
density.
o True
o False
2. Ratio between the density of the fluid to the density of the standard fluid is
o Specific weight
o Specific volume
o Specific gravity
3. The viscosity of liquids increases with the increase of temperature while the viscosity of gases
decreases with the temperature increase.
o True
o False
4. − − − − − is used to measure small differences in gas pressures.
o Piezometer tube.
o Differential manometer
o Inclined-tube manometer
o U-tube manometer
5. The pressure of fluid at rest is independent of pressure direction as long as there are no
shearing stresses present.
o True
o False
6. In − − − − − flow, the velocity at a given point may differ from other points along the
streamline but do not change with time.
o Uniform
o Non-uniform
o Steady
o Non-steady

7. When the application requires a great amount of power, pneumatic system is used.
o True
o False
8. − − − − − lies along the median line of the body which divides the shape into two equal
parts.
o Center of pressure (Cp)
o Centroid (C)
o Center of gravity (CG)
9. In laminar flow, each particle of the fluid follows a smooth path, usually at low velocities,
which never interferes with one another.
o True
o False
10. − − − − − is a control valve that reduces the input pressure of a fluid to a desired value
keeping the operating pressure constant.
o Relieve valve
o Regulator valve
o Check valve
o Shut off valve

Answer 1

Answer for question no. 1 :

True

Because, Density is directly proportional to pressure and indirectly proportional to temperature according to Ideal Gas Law (pV=RT).

As a whole when pressure and temperature ,both changes , density remains almost constant

Answer for question no.2 :

Specific Gravity

This is by definition of Specific Gravity that it is the ratio of density or weight of a fluid to the density or weight of standard fluid.

For liquids , standard fluid is water and for gases, the standard fluid is Oxygen

Answer for question no.3 :

False.

The correct statement is as follows.

Viscosity of liquids decreases with increase in temperature where as viscosity of gases increases with the increase in temperature.

Answer for question no.4 :

Inclined tube manometer.

The setup to measure small differences in gas pressures consists of a U tube manometer and difference of gases is applied to it. The overall setup is called as inclined tube manometer. It is used to measure very small differences in gas pressures where high accuracy is required.

Answer for question no. 5 :

True

As long as there are no shearing stresses, the fluid in rest experiences no external air pressure because the air pressure acts on both sides of the wall and cancels each other provided force must be perpendicular to the surface.

Answer for question no.6 :

Steady

Steady: fluid flow conditions when doesnot change with the time , it is called steady.

Here velocity is different at different points. But remains same with respect to time. So it is steady

Answer to question no.7 :

False

Because pneumatic circuits are run at low power. And most high power circuits use hydraulics.

Answer to question no.8 :

Centroid

This is by definition of centroid that it cuts into equal shapes.