Mini test 3 (Thủy lực)

• Đăng bởi: nguyenphuocbinh
• Sinh viên
• 18/01/2019

Test 3

1. For a fluid at rest:

A, the shear stress depends upon the coefficient of viscosity

B, the shear stress is maximum on a plane inclined at 45^o to horizontal

C, the shear stress is zero

D, the shear stress is zero only on horizontal planes

2. Indicate the incorrectanswer :

Hydrostatic pressure variation implies that :

A, the pressure varies linearly with depth

B, the piezometric head is constant

C, the density of the fluid is constant

D, pressure varies linearly with distance

3. Normal stressesare of the same magnitude in all directions at a point in a fluid :

A, only when the fluid is frictionless

B, only when the fluid is at rest

C, only when there is no shear stress

D, in all cases of fluid motion

4. In an isothermalatmosphere, the pressure:

A, decreases linearly with elevation

B, decreases exponentially with elevation

C, increases logarithmically with elevation

D, varies inversely as the density

5. The piezometric headin a staticliquid :

A, remains constant only on a horizontal plane

B, increases linearly with depth below a free surface

C, remains constant at all points in the fluid

D, decreases linearly with depth below the free surface

6. Identify the correctstatement :

A, Local atmospheric pressure is always less than the standard atmospheric pressure

B, Local atmospheric pressure depends only on the elevation of the place

C, A barometer reads the difference between the local and standard atmospheric pressure

D, Standard atmospheric pressure is 760 mm of mercury

7. Bourdon gaugemeasures :

A, absolute pressure

B, gauge pressure

C, local atmospheric pressure

D, standard atmospheric pressure

8. When the barometer reads 740 mm of mercury, a pressure of 10 kPa suction at that location is equivalent to :

A, 10.02 m of water (abs)

B, 9.87 m of water (abs)

C, 88.73 kPa (abs)

D, 0.043 kPa (abs)

9. The standard sea-level atmospheric pressureis equivalent to :

A, 10.0 m of fresh water of ρ = 998 kg/m³

B, 10.1 m of salt water of ρ = 1025 kg/m³

C, 12.5 m of kerosene of ρ = 800 kg/m³

D, 6.4 m of carbon tetrachloride of ρ = 1590 kg/m³

10. The standard atmospheric pressure is 760 mm of mercury. At a certain location the barometer reads 710 mm of mercury. At this place an absolute pressure of 360 mm of mercury corresponds to a gauge pressurein mm of mercury :

A, 400 mm of vacuum

B, 350 mm of vacuum

C, 360 mm of mercury

D, 710 mm