Question

relation between heat gain or loss by abody with surface area​

Answer 1

More surface area means more space for heat to leave the body. I'm guessing the "less volume" part means you want more surface area while keeping the volume the same (eg breaking an ice cube to create more surface area but keeping the same exact volume).

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Answer 2

Heat Loss or Heat Gain.

Heat tends to flow from higher temperatures to lower temperature zones by conduction, convection and radiation. The rate of heat flow by any of these three forms is determined by the temperature difference between the two zones or areas considered.