Answer:
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answer : Doubling the Diameter increases the heat transfer rate by a factor of 4 ( B )
Explanation:
The heat transfer in the axial direction of the cylinder can be calculated/determined as attached below
[tex]\frac{q_{2} }{q_{1} } = \frac{(2D)^2}{D^2}[/tex]
[tex]q_{2}[/tex] = 4[tex]q_{1}[/tex] ( This shows that Doubling the diameter increases the heat transfer rate by a factor of 4 )