The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is___________________?

Related Mcqs:

1. A hydraulic press has a ram of 10 cms in diameter and a plunger of 1 cm in diameter. The force required on the plunger to raise a weight of 10 tons on the ram is _____________ kg?

   A. 10
   B. 100
   C. 1000
   D. 10000

2. The fluid jet discharging from a 2″ diameter orifice has a diameter of 1.75″ at its venacontracta. The co-efficient of contraction is___________________?

   A. 1.3
   B. 0.766
   C. 0.87
   D. None of these

3. The hydraulic radius for flow in a rectangular duct of cross-sectional dimension H, W is___________________?

   A. √(HW/π)
   B. HW/2 (H + W)2
   C. HW/4 (H + W)2
   D. 2HW/(H + W)

4. Hydraulic diameter for non-circular ducts is equal to ___________ times the area of flow divided by the perimeter?

   A. Two
   B. Three
   C. Four
   D. Eight

5. Hydraulic mean depth (Dm) for a circular pipe of diameter ‘D’ flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum ?

   A. Flow rate
   B. Mean velocity
   C. Both ‘a’ & ‘b’
   D. Neither ‘a’ nor ‘b’

6. The ratio of the hydraulic radius to the diameter of the channel, for maximum mean velocity of flow in a circular channel, in open channel flow is_________________?

   A. 0.3
   B. 0.9
   C. 0.03
   D. 0.66

7. The equivalent diameter for flow through a rectangular duct of width B and height H is___________________?

   A. HB/2 (H + B)
   B. HB/(H + B)
   C. 2HB/(H + B)
   D. 4HB/(H + B)

8. For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as_________________?

   A. d
   B. d2
   C. d4
   D. d̅ 2

9. 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

10. With increase in the ratio of orifice diameter to pipe diameter, the fraction of the orifice pressure differential that is permanently lost________________?

    A. Increases
    B. Decreases
    C. Remains unchanged
    D. Increases exponentially