Question

If the temperature of the surrounding is increased keeping all other parameters constant, then the rate of heat transfer from a comparatively hotter body due to convection will

• A. not change
• B. increase
• C. decrease
• D. first increases then decreases

Answer 1

The correct option is C decrease

We know that, rate of heat transfer in convection, $q=h_{c}A\Delta T$ ..............(1)
where $h_c$ is convection coefficient, $A$ is surface area of body and $\Delta T=$ temperature difference between body and surrounding.
$\Rightarrow \Delta T=T-T_o$
As surrounding temperature $T_o$ increases, $\Delta T$ will decrease.
Thus, rate of heat transfer $q$ will decrease. $[$ from (1) $]$