Which of the followings is a wrong statement?The shape factor is equal...
For a flat or convex surface, the shape factor with respect to itself is zero. This aspect stems from the fact that for any part of flat or convex surface, one cannot see any other part of the same surface.
View all questions of this test
Which of the followings is a wrong statement?The shape factor is equal...
In this question, we are given a series of statements about the shape factor and we need to identify the wrong statement. Let's analyze each statement and determine if it is correct or incorrect.
a) "The shape factor is equal to one for any surface completely enclosed by another surface."
This statement is correct. When a surface is completely enclosed by another surface, the shape factor between them is equal to one. This means that all the heat generated by the inner surface is absorbed by the outer surface, without any heat escaping to the surroundings.
b) "The shape factor is equal to one for infinite parallel planes radiating only to each other."
This statement is correct. When we have an infinite number of parallel planes that are radiating heat only to each other, the shape factor between them is equal to one. This implies that the heat exchange between the planes is balanced, with no heat loss to the surroundings.
c) "The shape factor is equal to one for a flat or convex surface with respect to itself."
This statement is correct. When we consider a flat or convex surface with respect to itself, the shape factor is equal to one. This means that all the heat generated by the surface is absorbed by the surface itself, without any heat escaping to the surroundings.
d) "The shape factor is equal to one inside a cylinder to the outer cylinder of a long co-axial cylinder."
This statement is incorrect. The shape factor between the inner and outer cylinders of a long co-axial cylinder is not equal to one. In this case, the shape factor depends on the ratio of the inner and outer radii, as well as the length of the cylinder. The shape factor will be different from one unless the inner and outer cylinders have the same radius.
Therefore, the correct answer is option 'D' - "Inside cylinder to outer cylinder of a long co-axial cylinder."