Answer: Option (b) is the correct answer.
Explanation:
Kinetic energy is defined as the energy obtained by the molecules of an object due to their motion.
Also, it is known that kinetic energy is directly proportional to temperature.
Mathematically, K.E =
where, T = temperature
Whereas potential energy is defined as the energy obtained by an object due to its position.
Mathematically, P.E = mgh
where, m = mass
g = acceleration due to gravity
h = height
Therefore, in the given curve when temperature remains constant then kinetic energy of molecules will also remain.
Hence, we can conclude that the segment QR represents an increase in the potential energy, but no change in the kinetic energy.