Which of the following statements is true for a cyclic process?
(a)$\partial \mathrm{q}=0$
(b)$\partial \mathrm{w}=0$
(c)Heat can be completely converted into work
(d)Work can be completely converted into heat
Answer
Answer: D ✓ checked by 4AB · confidence high
Explanation
In a cycle ΔU = 0 so q = −w, but neither need be zero; work can be converted completely into heat (e.g. friction), whereas heat cannot be converted completely into work (second law).