SAT Subject Physics Practice Question 264: Answer and Explanation
35. A student is monitoring the pressure and absolute temperature in a container of fixed volume filled with an ideal gas as the gas is heated. Which of the following graphs best illustrates the relationship between the pressure (P) and absolute temperature (T) of the gas, assuming that none of the gas escapes from the container?
Correct Answer: C
The ideal gas law says that PV = nRT. Since V, n, and R are constants here, P is proportional to T. The graph of a proportion is a straight line through the origin.