Question

The rate of heat increase in a system depends on __________

(a) the rate of heat transferred to the system

(b) the rate of heat generated by the system

(c) neither the rate of heat generated by the system nor the rate of heat transferred to the system

(d) both the rate of heat transferred to the system and the rate of heat generated by the system

This question was posed to me in an interview for internship.

I would like to ask this question from Energy Equation topic in section Governing Equations of Fluid Dynamics of Computational Fluid Dynamics

Answer 1

The correct choice is (d) both the rate of heat transferred to the system and the rate of heat generated by the system

To explain I would say: Heat can be added to a system in two ways:

 Transfer of heat across the surface of the element by surface forces.

 The heat generated by the system itself.