## Fluid Mechanics and Hydraulic Machinery Miscellaneous

#### Fluid Mechanics and Hydraulic Machinery

1. A circular plate 1 m in diameter is submerged vertically in water such its upper edge is 8 m below the free surface of water. The total hydro static pressure force on one side of plate is

1.  h = 8 + d 2

 = 8 + d = 8.5 m 2

Surface area,
 A = π d2 = 3.14 × 12 = 0.785 m2 4 4

Total hydrostatic pressure force, F = ρghA
F = 1000 × 9.81 × 8.5 × 0.785 = 65458 N
or F = 65.45 KN

##### Correct Option: B

 h = 8 + d 2

 = 8 + d = 8.5 m 2

Surface area,
 A = π d2 = 3.14 × 12 = 0.785 m2 4 4

Total hydrostatic pressure force, F = ρghA
F = 1000 × 9.81 × 8.5 × 0.785 = 65458 N
or F = 65.45 KN

1. Kinematic viscosity of air at 20°C is given to be 1.6 × 10-5 m2/s. Its kinematic viscosity at 70°C will be varying approximately

1. Viscosity of gas increases with increasing temperature.

##### Correct Option: A

Viscosity of gas increases with increasing temperature.

1. Assuming constant temperature condition and air to be an ideal gas, the variation in atmospheric pressure with height calculated from fluid statics is

1. NA

##### Correct Option: B

NA

1. For a Newtonian fluid

1. For a Newtonian fluid, shear stress is proportional to rate of shear strain.

##### Correct Option: C

For a Newtonian fluid, shear stress is proportional to rate of shear strain.

1. Kaplan water turbine is commonly used when the flow through its runner is

1. Kaplan turbine is an axial flow turbine and works at low heads (<50).

##### Correct Option: B

Kaplan turbine is an axial flow turbine and works at low heads (<50).