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Chapter-12: Thermodynamics

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

  • Internal energy
  • Heat content
  • Pressure
  • Temperature
Answer
Pressure

2. Internal energy of an isolated system

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

3. First Law of Thermodynamics leads to –

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

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

  • Mass
  • Linear momentum
  • Energy
  • Angular momentum
Answer
Energy

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

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

6. In the isochoric process

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

7. In the isothermal process –

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

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

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

9. In an isobaric process –

  • Pressure increases
  • Pressure decreases
  • Pressure neither increases or decreases (P fixed)
  • None of these.
Answer
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 %
Answer
25 %

11. An adiabatic process occurs at constant –

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

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

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

13. A refrigerator is –

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