What can be the answer

Question

Q.1 choose correct option

a) Only heat can cross the boundary of control surface.

b) Heat and Work can cross the boundary of control surface.

c) Mass as well as heat and work can cross the boundary of control surface.

d) None of these.

Answer 1

That depends upon who is asking.

First, I have never heard the term "control surface" but I assume it refers to the boundary of the system of interest.

Second, heat and work are not substances that transfer across boundaries. Energy, through heat transfer or work, crosses a boundary, but not work/heat itself.

However, assuming I am not reading too much into the semantics, then all three. If the person asking does distinguish heat/work from energy as they should, then it would be option d.