Hydraulics And Fluid Mechanics In Me - Practice Test

[#141] Mach number is significant in

(A) Supersonics, as with projectiles and jet propulsion

(B) Full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.

(C) Simultaneous motion through two fluids where there is a surface of discontinuity, gravity force, and wave making effects, as with ship's hulls

(D) All of the above

Correct Answer

(A) Supersonics, as with projectiles and jet propulsion

[#142] A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?

(A) The metal piece will simply float over the mercury

(B) The metal piece will be immersed in mercury by half

(C) Whole of the metal piece will be immersed with its top surface just at mercury level

(D) Metal piece will sink to the bottom

Correct Answer

(C) Whole of the metal piece will be immersed with its top surface just at mercury level

[#143] A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?

(A) 0.5

(B) 0.4

(C) 0.515

(D) 0.3

Correct Answer

(C) 0.515

[#144] The power transmitted through a pipe is (where w = Specific weight in N/m 3 and Q = Discharge in m 3 /s)

(A) $${ ext{w}} imes { ext{Q}} imes { ext{H}}$$

(B) $${ ext{w}} imes { ext{Q}} imes {{ ext{h}}_{ ext{f}}}$$

(C) $${ ext{w}} imes { ext{Q}}left( {{ ext{H}} - {{ ext{h}}_{ ext{f}}}} ight)$$

(D) $${ ext{w}} imes { ext{Q}}left( {{ ext{H}} + {{ ext{h}}_{ ext{f}}}} ight)$$

Correct Answer

(C) $${ ext{w}} imes { ext{Q}}left( {{ ext{H}} - {{ ext{h}}_{ ext{f}}}} ight)$$

[#145] In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

(A) Designing new impeller

(B) Trimming the impeller size to the required size by machining

(C) Not possible

(D) Some other alterations in the impeller

Correct Answer

(B) Trimming the impeller size to the required size by machining

Hydraulics And Fluid Mechanics In Me - Study Mode

[#141] Mach number is significant in

Correct Answer

[#142] A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?

Correct Answer

[#143] A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?

Correct Answer

[#144] The power transmitted through a pipe is (where w = Specific weight in N/m 3 and Q = Discharge in m 3 /s)

Correct Answer

[#145] In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

Correct Answer