Questions and answers for exam Preparation

MCQs

Total Questions : 63 | Page 1 of 7 pages

Question 1. Kirk bride criterion is given by

h = 0.0057 (Re)^0.4 [k³ p² g/δ²]^1/3
h = 0.0067 (Re)^0.4 [k³ p² g/δ²]^1/3
h = 0.0077 (Re)^0.4 [k³ p² g/δ²]^1/3
h = 0.0087 (Re)^0.4 [k³ p² g/δ²]^1/3

Discuss Question

Answer: Option C. -> h = 0.0077 (Re)^0.4 [k³ p² g/δ²]^1/3
Answer: (c).h = 0.0077 (Re)^0.4 [k³ p² g/δ²]^1/3

Question 2. The bubble diameter at the time of detachment from the surface can be worked out from the relation proposed by

Stanton
Fritz
Fourier
Nusselt

Discuss Question

Answer: Option B. -> Fritz
Answer: (b).Fritz

Question 3. Consider the following phenomena
(i) Boiling
(ii) Free convection in air
(iii) Forced convection in air
(iv) Conduction in air
Identify the correct sequence (heat transfer coefficient)

3 – 4 – 1 – 2
4 – 1 – 3 – 2
4 – 3 – 2 – 1
4 – 2 – 3 – 1

Discuss Question

Answer: Option D. -> 4 – 2 – 3 – 1
Answer: (d).4 – 2 – 3 – 1

Question 4. For n-tubes in a vertical column of the tube bank pattern, identify the correct statement.
(Where, D is the diameter of a single tube in the bank)

D e = n D
D e = n² D
D e = (1/n) D
D e = D

Discuss Question

Answer: Option A. -> D e = n D
Answer: (a).D e = n D

Question 5. The nucleate pool boiling is influenced by the following factors
(i) Pressure
(ii) Liquid properties
(iii) Material
Identify the correct statements

1, 2 and 3
2 only
1 and 2
2 and 3

Discuss Question

Answer: Option A. -> 1, 2 and 3
Answer: (a).1, 2 and 3

Question 6. With increase in excess temperature, the heat flux in boiling

Increases continuously
Decreases and then increases
Decreases, then increases and again decreases
Increases, then decreases and again increases

Discuss Question

Answer: Option D. -> Increases, then decreases and again increases
Answer: (d).Increases, then decreases and again increases

Question 7. In spite of large heat transfer coefficient in boiling liquids, fins are used advantageously when the entire surface is exposed to

Film boiling
Transition boiling
Nucleate boiling
All modes of boiling

Discuss Question

Answer: Option D. -> All modes of boiling
Answer: (d).All modes of boiling

Question 8. The bubble diameter at the time of detachment from the surface can be worked out from the relation proposed by Fritz and is given by
(Where, β is the angle of contact)