Fluid Mechanics

301.In isotropic turbulence, the _________ are equal to each other.

  1. Temporal velocity components
  2. Mean square of velocity fluctuations in the three co-ordinate directions
  3. Root mean square of velocity fluctuations in the three co-ordinate directions
  4. None of these
Correct answer: (B)
Mean square of velocity fluctuations in the three co-ordinate directions

302.In laminar flow through a round tube, the discharge varies

  1. Linearly as the viscosity
  2. Inversely as the pressure drop
  3. Inversely as the viscosity
  4. As the square of the radius
Correct answer: (C)
Inversely as the viscosity

303.In magnetic flow meters, voltage generation is

  1. Due to the motion of conducting fluid through an externally generated uniform field
  2. Proportional to the fluid velocity
  3. Both (A) and (B)
  4. Neither (A) nor (B)
Correct answer: (C)
Both (A) and (B)

304.In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is

  1. 0.44
  2. 0.044
  3. 4.4
  4. 44
Correct answer: (A)
0.44

305.In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the _________ of its diameter.

  1. Inverse
  2. Square root
  3. Second power
  4. First power
Correct answer: (B)
Square root

306.In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is

  1. 0.5
  2. 0.84
  3. 1.84
  4. 1.25
Correct answer: (C)
1.84

307.In parallel pipe problems, the

  1. Head loss is the same through each pipe
  2. Discharge is the same through all the pipes
  3. Total head loss is equal to the sum of the head losses through each pipe
  4. None of these
Correct answer: (A)
Head loss is the same through each pipe

308.In power law, ξ = [A (du/dy)2 + B] then the fluid is

  1. Newtonian
  2. Dilatant
  3. Thixotropic
  4. Rheopectic
Correct answer: (A)
Newtonian

309.In the complete turbulence zone (in rough pipes), the

  1. Rough and smooth pipes have the same friction factor
  2. Laminar film covers the roughness projections
  3. Friction factor depends upon NRe only
  4. Friction factor is independent of the relative roughness
Correct answer: (D)
Friction factor is independent of the relative roughness

310.In the laminar boundary layer flow over a flat plate, the ratio (Δ/x) varies as: (where, 'Δ' is the boundary layer thickness and 'x' is the distance from the leading edge in the direction of flow).

  1. Re
  2. √Re
  3. 1/Re
  4. Re -1/2
Correct answer: (D)
Re -1/2
Page 31 of 73