Question

The following graph is constructed for a fixed amount of gas. Which of the following options are correct:

• A. From 1-2, pressure will increase
• B. From 2-3, pressure remains constant
• C. Gas pressure at point 3 is greater than point 1
• D. From 1-2, pressure will decrease

Answer 1

Answer: (A), (B), (C)

The correct options are
A From 1-2, pressure will increase
B From 2-3, pressure remains constant
C Gas pressure at point 3 is greater than point 1

a) From state 1 to state 2, volume of the gas decreases with increase in temperature. This is only possible only if there is an increase of pressure as well.
b) There is a linear relationship between V and T. This indicates, pressure is constant, since at constant pressure
$V=KT$ . Hence the plot of V vs T is a straight line.

c) Since, $P_2>P_1$ and $P_3=P_2$. So, the pressure at state 3 is greater than at state 1.
d) From (a), this statement is wrong.