試題詳解

9. Which of the following statements about absolute pressure P, gauge pressure P_G and atmospheric pressure P₀is true?
(A) P is the same as P_G at 273 K.
(B) P₀ + P_G is the absolute pressure P.
(C) Gauge pressure P_G is always positive.
(D) Absolute pressure P is the atmospheric pressure P₀ at 15°C.
(E) None of the above.