# CHAPTER-12: THERMODYNAMICS

1. The zeroth law of thermodynamics leads to the concept of

• Internal energy
• Heat content
• Pressure
• Temperature
Pressure

2. Internal energy of an isolated system

• Increases
• Decreases
• Remains the same
• None of these
Remains the same

3. First Law of Thermodynamics leads to –

• Conservation of mass
• Conservation of linear momentum
• Conservation of energy
• Conservation of angular momentum.
Conservation of energy

4. First law of thermodynamics is the law of Conservation of –

• Mass
• Linear momentum
• Energy
• Angular momentum
Energy

5. Which of the following is conserved in the first law of thermodynamics?

• Number of molecules
• Energy
• Temperature
• Heat.
Energy

6. In the isochoric process

• Pressure = Constant
• Volume = Constant
• Temperature = Constant
• Pressure and Volume both constant
Volume = Constant

7. In the isothermal process –

• Temperature increases
• Temperature decreases
• Temperature neither increases nor decreases
• Volume remains the same
Temperature neither increases nor decreases

8. In a cyclic process, the internal energy of the gas –

• increases
• decreases
• remains constant
• becomes zero.
remains constant

9. In an isobaric process –

• Pressure increases
• Pressure decreases
• Pressure neither increases or decreases (P fixed)
• None of these.
Pressure neither increases or decreases (P fixed)

10. Find the efficiency of a Carnot’s engine working between 127°C and 27°C?

• 35 %
• 25 %
• 50 %
• 60 %
25 %

11. An adiabatic process occurs at constant –

• Temperature
• Pressure
• Heat
• None of these.
Heat

12. The efficiency of a Carnot engine depends on the temperature of –

• Source only
• Working substance
• Sink only
• Source and sink
Sink only

13. A refrigerator is –

• an electric motor
• a heat engine
• a heat engine working back
• an air cooler. 