In an adiabatic process, what is true about heat transfer?

• A. Heat exchange occurs
• B. Work is zero
• C. Temperature remains constant
• D. No heat exchange with surroundings

Answer: (D)

An adiabatic process is defined by no heat transfer between the system and its surroundings. Because the heat exchanged, q, is zero, any change in the system’s internal energy comes from work done on or by the system, not from heat flow. That means the temperature can change as the system does work or is compressed, even though nothing enters or leaves as heat. So the statement that there is no heat exchange with the surroundings accurately describes an adiabatic process. The other ideas aren’t generally true: heat exchange would violate the adiabatic condition, nonzero work can occur even with q = 0, and temperature does not have to stay constant in an adiabatic process (that would be isothermal).