MCQOPTIONS
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MCQOPTIONS
This section includes 3 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A cylinder of radius r and made of material of thermal conductivity k 1 is surrounded by a cylindrical shell of inner radius r and outer radius 2r. This outer shell is made of a material of thermal conductivity k 2. Net conductivity would be |
| A. | k 1 + 3 k 2/4 |
| B. | k 1 + k 2/4 |
| C. | k 1 + 3k 2 |
| D. | k 1 + k 2 |
| Answer» B. k 1 + k 2/4 | |
| 2. |
The heat flow equation through a cylinder of inner radius r1 and outer radius r2 is desired to be written in the same form as that for heat flow through a plane wall. For wall thickness (r 2-r 1) the area will be |
| A. | A1 + A2/2 |
| B. | A1 + A2 |
| C. | A2 – A1/ log e (A2/A1) |
| D. | A1 + A2/2 log e (A2/A1) |
| Answer» B. A1 + A2 | |
| 3. |
A steel pipe of 20 mm inner diameter and 2 mm thickness is covered with 20 mm thick of fiber glass insulation (k = 0.05 W/m degree). If the inside and outside convective coefficients are 10 W/m2 degree and 5 W/m2 degree, calculate the overall heat transfer coefficient based on inside diameter of pipe. In the diagram, the diameter of small circle is 20 mm |
| A. | 1.789 W/m2 degree |
| B. | 2.789 W/m2 degree |
| C. | 3.789 W/m2 degree |
| D. | 4.789 W/m2 degree |
| Answer» C. 3.789 W/m2 degree | |