21. | “Radiation cannot be affected through vacuum or space devoid of any matter”. True or false |
a. | True |
b. | False |
c. | May be |
d. | Can't say |
View Answer Report Discuss 50-50! |
Answer: (b).False
|
22. | A composite slab has two layers having thermal conductivities in the ratio of 1:2. If thickness is same for each layer then the equivalent thermal conductivity of the slab would be |
a. | 1/3 |
b. | 2/3 |
c. | 2 |
d. | 4/3 |
View Answer Report Discuss 50-50! |
Answer: (d).4/3
|
23. | A composite wall of a furnace has two layers of equal thickness having thermal conductivities in the ratio 2:3. What is the ratio of temperature drop across the two layers? |
a. | 2:3 |
b. | 3:2 |
c. | 1:2 |
d. | log e 2 : log e 3 |
View Answer Report Discuss 50-50! |
Answer: (b).3:2
|
24. | Typical examples of heat conduction through cylindrical tubes are not found in |
a. | Power plants |
b. | Oil refineries |
c. | Most process industries |
d. | Aircrafts |
View Answer Report Discuss 50-50! |
Answer: (d).Aircrafts
|
25. | The rate of heat conduction through a cylindrical tube is usually expressed as |
a. | Per unit length |
b. | Per unit area |
c. | Only length |
d. | Only area |
View Answer Report Discuss 50-50! |
Answer: (a).Per unit length
|