Q.1
Which parameter is responsible for the commencement of the turbulent flow?
  • a) Fourier number
  • b) Reynolds number
  • c) Stanton number
  • d) Nusselt number
Q.2
The transition from laminar to turbulent flow occurs at a critical Reynolds number of
  • a) 1800
  • b) 2200
  • c) 2600
  • d) 3000
Q.3
A condenser is to be designed to condense 225.0 kg of steam per hour at a pressure of 0.bar. A square array oftubes, each of 6 mm in diameter, is available for the task. If the tube surface temperature is to be maintained atdegree Celsius, make calculations for the length of the tube
  • a) 4.353 m
  • b) 3.353 m
  • c) 2.353 m
  • d) 1.353 m
Q.4
The outer surface of a vertical tube is 1.m long and outer diameter ismm is exposed to saturated steam at atmospheric pressure. If the tube surface is maintained atdegree Celsius by the flow of cooling water through it, determine the rate of heat transfer to the coolant
  • a) 47648 W
  • b) 12345 W
  • c) 19879 W
  • d) 97123 W
Q.5
Consider the above problem, find the rate at which steam is condensed at the tube surface
  • a) 7.7 * 10 -3
  • b) 8.7 * 10 -3
  • c) 9.7 * 10 -3
  • d) 10.7 * 10 -3
Q.6
What is the value of characteristics length in turbulent film condensation?
  • a) δ
  • b) 3 δ
  • c) 2 δ
  • d) 4 δ
Q.7
What is the value of Reynolds number in terms of mass flow rate?
  • a) 4 m/δ b
  • b) 2 m/δ b
  • c) 3 m/δ b
  • d) m /δ b
Q.8
Kirk bride criterion is given by
  • a) h = 0.0057 (Re) 0.4 [k 3 p 2 g/δ 2] 1/3
  • b) h = 0.0067 (Re) 0.4 [k 3 p 2 g/δ 2] 1/3
  • c) h = 0.0077 (Re) 0.4 [k 3 p 2 g/δ 2] 1/3
  • d) h = 0.0087 (Re) 0.4 [k 3 p 2 g/δ 2] 1/3
Q.9
The relation between relative effectiveness of horizontal and vertical tubes as condensing surfaces is given by
  • a) h h/h v = 0.768 (l/d)
  • b) h h/h v = 0.768 (l/d) 0.25
  • c) h h/h v = 0.768 (l/d) 0.5
  • d) h h/h v = 0.768 (l/d) 1.25
Q.10
For n-tubes in a vertical column of the tube bank pattern, identify the correct statement
  • a) D e = n D
  • b) D e = n 2 D
  • c) D e = (1/n) D
  • d) D e = D
0 h : 0 m : 1 s