Q.1
Which of the following is the correct form of Stoke’s law?
  • a) CD = 24 / NRe
  • b) CD = 24 * NRe
  • c) CD = 18 / NRe
  • d) CD = 18 * NRe
Q.2
What is the value of CD corresponding to a Reynold’s number between 5 and 1000?
  • a) 0.3
  • b) 0.4
  • c) 0.2
  • d) 0.1
Q.3
Under which condition, is the Cunningham correction factor applicable for very small particles?
  • a) When particle size is far greater than the gas mean free path
  • b) When particle size is far lesser than the gas mean free path
  • c) When particle size becomes comparable to the gas mean free path
  • d) Cunningham factor is applicable for small particles under all conditions
Q.4
Under which circumstances is the Oseen formula valid for drag coefficient?
  • a) When the Reynolds number is between 0.3 and 5
  • b) When the Reynolds number is between 0.2 and 4
  • c) When the Reynolds number is between 0.3 and 4
  • d) When the Reynolds number is between 0.2 and 5
Q.5
The total drag is a sum of the skin drag and the pressure drag. Which among of the following options, states the correct formula for skin drag and pressure drag?
  • a) 2πµDU, 2πµDU
  • b) 1πµDU, 2πµDU
  • c) 2πµDU, πµDU
  • d) 3πµDU, πµDU
Q.6
What are the dimensions of drag coefficient?
  • a) Dimensionless
  • b) MLT-2
  • c) ML-3
  • d) L
Q.7
Let FG be the gravitational force, FD be the drag force and FB be the buoyant force. Which of the following best describes the relation between these forces when a sphere falls into a fluid with terminal velocity?
  • a) FG + FD = FB
  • b) FG + 2FB = FD
  • c) 2FB + FD = FG
  • d) FB + FD = FG
Q.8
Calculate the drag force on a ball of diameter of 80mm, flowing through air. The density of air is 1.kg/m3 and the ball flows with a velocity of 7m/s. The Reynolds number is 3730.
  • a) 0.077 N
  • b) 76969 N
  • c) 0.011 N
  • d) 10995 N
Q.9
Which component of the total force is perpendicular to the direction of motion? What are the dimensions of this component?
  • a) Lift, MLT-1
  • b) Drag MLT
  • c) Drag, MLT-2
  • d) Lift, MLT-2
Q.10
Select the incorrect statement.
  • a) Drag depends inversely on mass
  • b) Drag is independent of shape
  • c) Drag linearly depends on velocity
  • d) Drag depends on compressibility
0 h : 0 m : 1 s