Fluid Mechanics and Hydraulic Machinery Miscellaneous

Fluid Mechanics and Hydraulic Machinery Miscellaneous

Easy Questions
Moderate Questions
Difficult Questions

Fluid Mechanics and Hydraulic Machinery

Fluid Mechanics and Hydraulic Machinery Miscellaneous
  1. A large tank with a nozzle attached contains three immiscible, inviscid fluids as shown. Assuming that the changes in h1, h2 and h3 are negligible, the instantaneous discharge velocity is








  1. View Hint View Answer Discuss in Forum

    Applying Bernoulli’s equation at exit, we get

    P1
    		 + gz1 +
    V1²
    		 =
    P1
    		 + gz2 +
    V2²
    ρ32ρ32

    We know Z1 = Z2, V1 = 0 & P2 = Patm
    Hence it reduce to
    P1
    		 =
    V2²
    ρ32

    Correct Option: A

    Applying Bernoulli’s equation at exit, we get

    P1
    		 + gz1 +
    V1²
    		 =
    P1
    		 + gz2 +
    V2²
    ρ32ρ32

    We know Z1 = Z2, V1 = 0 & P2 = Patm
    Hence it reduce to
    P1
    		 =
    V2²
    ρ32

  1. The difference in pressure (in N/m2) across an air bubble of diameter 0.001 m immersed in water (surface tension = 0.072 N/m) is_____.








  1. View Hint View Answer Discuss in Forum


    Surface tension in a bubble =
    Δp.r
    4

    we know, Pi – Po =
    4T
    r

    Δp =
    4 × 0.072
    		= 288 N/m2.
    0.01

    Correct Option: B


    Surface tension in a bubble =
    Δp.r
    4

    we know, Pi – Po =
    4T
    r

    Δp =
    4 × 0.072
    		= 288 N/m2.
    0.01

  1. An inverted U-tube manometer is used to measure the pressure difference between two pipes A and B, as shown in the figure. Pipe A is carrying oil (specific gravity = 0.8) and pipe B is carrying water. The densities of air and water are 1.16 kg/ m3 and 1000 kg/m3, respectively. The pressure difference between pipes A and B is________kPa.
    Acceleration due to gravity: g = 10 m/s2








  1. View Hint View Answer Discuss in Forum

    PA −(ρoil × g × 0.2) − (ρair × g × 0.08) + (ρw × g × 0.38) − PB = 0

    Correct Option: A

    PA −(ρoil × g × 0.2) − (ρair × g × 0.08) + (ρw × g × 0.38) − PB = 0

Direction: A smooth flat plate with a sharp leading edge is placed along a gas stream flowing at U = 10 m/s. The thickness of the boundary layer at section r – s is 10 mm, the breadth of the plate is 1 m (into the paper) and the density of the gas, ρ = 1.0 kg/m3. Assume that the boundary layer is thin, two-dimensional, and follows a linear velocity distribution, u = U (y/δ), at the section r–s, where y is the height from plate.

  1. The integrated drag force (in N) on the plate, between p – s, is








  1. View Hint View Answer Discuss in Forum

    By momentum equation, we can find drag force.

    Correct Option: C

    By momentum equation, we can find drag force.

  1. The mass flow rate (in kg/s) across the section q – r is








  1. View Hint View Answer Discuss in Forum

    Mass entering from side q-p = Mass leaving from side q-r + Mass leaving the side r-s

    Correct Option: B

    Mass entering from side q-p = Mass leaving from side q-r + Mass leaving the side r-s