A rectangular surface 3′ × 4′, has the lower 3 edge horizontal and 6′ below a free oil surface (sp. gr. 0.8). The surface inclination is 300 with the horizontal. The force on one side of the surface is (where, y = specific weight of water) ?

Related Mcqs:

1. The location of centre of pressure, which defines the point of application of the total pressure force on the surface, can be calculated by applying the principle of moments according to which “sum of the moment of the resultant force about an axis is equal to the sum of the components about the same axis”. The centre of pressure of a rectangular surface (of width ‘w’) immersed vertically in a static mass of fluid is at a depth of (where, y = depth of the liquid) ?

   A. 1/(y/3)
   B. 2y/3
   C. 1/(y/4)
   D. 3y/4

2. A centrifugal pump is used to pump water through a horizontal distance of 150 m, and then raised to an overhead tank 10 m above. The pipe is smooth with an I.D of 50 mm. What head (m of water) must the pump generate at its exit E. to deliver water at a flow rate of 0.001 m3/s? The Fanning friction factor, f is 0.0062 ?

   A. 10 m
   B. 11 m
   C. 11.8 m
   D. 30 m

3. A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity ?

   A. Same as that of A
   B. One fourth as that of A
   C. Twice as that of A
   D. Four times as that of A

4. Which of the following relationship is valid for the equilibrium position of the float in a Rotameter? (Where, Df= Drag force on the float Bf = Buoyant force on the float Wf = Weight of the float)?

   A. Df + Bf = Wf
   B. Df = Bf + Wf
   C. Df + Bf + Wf =0
   D. None of these

5. A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 103 VOM + 10.94 × 106 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ?

   A. 0.2
   B. 0.5
   C. 0.7
   D. 0.8

6. A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 103 VOM + 10.94 × 106 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is_________________?

   A. 12 mm/s
   B. 16 mm/s
   C. 24 mm/s
   D. 28 mm/s

7. A centrifugal pump used to pump water is used to pump an oil with specific gravity of 0.8 at the same rate. The power consumption will now_________________?

   A. Increase
   B. Decrease
   C. Remain same
   D. Data insufficient to predict

8. A mercury (specific gravity = 13.6) manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be _______________ cms?

   A. 17
   B. 42
   C. 84
   D. 1.8

9. Which of the following is used for pumping crude oil from oil well ?

   A. Single stage centrifugal pump
   B. Gear pump
   C. Screw pump
   D. Duplex/triplex reciprocating pump

10. What is the force required (in Newtons) to hold a spherical balloon stationary in water at a depth of H from the air-water interface? The balloon is of radius 0.1 m and is filled with air ?

    A. 4πg/3
    B. 0.01 πgH/4
    C. 0.01 πgH/8
    D. 0.04 πgH/3