Question

Water _________ decreases with an increase in temperature.

(a) volume

(b) density

(c) pressure

(d) force

This question was addressed to me at a job interview.

This question is from Ocean Thermal Energy Conversion topic in division Ocean Energy & Geothermal Energy of Energy Engineering

Answer 1

Right answer is (b) density

To explain I would say: Water density decreases with an increase in temperature. Thus, there will be no thermal convection currents between the warmer, lighter water at the top and the deep cooler, heavier water. Thermal conduction heat transfer between them, across the large depths, is too low and thus mixing is retarded, so the warm water stays at the top and cool water stays at the bottom.