Q. In a Carnot cycle, what is the efficiency dependent on?
A.
The work done by the system
B.
The temperatures of the hot and cold reservoirs
C.
The type of working fluid
D.
The pressure of the system
Solution
The efficiency of a Carnot cycle is given by the formula η = 1 - (T_c/T_h), where T_c is the temperature of the cold reservoir and T_h is the temperature of the hot reservoir.
Correct Answer:
B
— The temperatures of the hot and cold reservoirs
Q. What is the maximum efficiency of a Carnot engine operating between two temperatures?
A.
100%
B.
Depends on the working fluid
C.
1 - (T_c/T_h)
D.
1 - (T_h/T_c)
Solution
The maximum efficiency of a Carnot engine is given by the formula η = 1 - (T_c/T_h), where T_c is the cold reservoir temperature and T_h is the hot reservoir temperature.
Q. What is the second law of thermodynamics primarily concerned with?
A.
Conservation of energy
B.
Direction of heat transfer
C.
Work done by a system
D.
Temperature of a system
Solution
The second law of thermodynamics states that heat cannot spontaneously flow from a colder body to a hotter body, which defines the direction of heat transfer.
Q. Which property is NOT a characteristic of pure substances?
A.
Defined melting point
B.
Defined boiling point
C.
Variable specific heat
D.
Single chemical composition
Solution
Pure substances have a defined melting point and boiling point, and they consist of a single chemical composition, but their specific heat can vary with temperature.
