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Mechanical Engineering :: Thermodynamics

  1. Brayton cycle consists' of following four processes

  2. A.

     Two isothermal and two isentropic

    B.

     Two isentropic and two constant volumes

    C.

     Two isentropic, one constant volume and one constant pressure

    D.

     Two isentropic and two constant pressures


  3. When coal is first dried and then crushed to a fine powder by pulverizing machine, the resulting fuel is called

  4. A.

     Wood charcoal

    B.

     Bituminous coal

    C.

     Briquetted coal

    D.

     None of these


  5. For reversible adiabatic process, change in entropy is

  6. A.

     Maximum

    B.

     Minimum

    C.

     Zero

    D.

     Negative


  7. If a system after undergoing a series of processes, returns to the initial state then

  8. A.

     Process is thermodynamically in equilibrium

    B.

     Process is executed in closed system cycle

    C.

     Its entropy will change due to irreversibility

    D.

     Sum of heat and work transfer will be zero


  9. The value of one bar (in S. I. units) is equal to

  10. A.

     1 × 102 N/m2

    B.

     1 × 103 N/m2

    C.

     1 × 104 N/m2

    D.

     1 × 105 N/m2


  11. The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible manner, is known as

  12. A.

     Enthalpy

    B.

     Internal energy

    C.

     Entropy

    D.

     External energy


  13. Which of the following is a reversible non-flow process?

  14. A.

     Isochoric process

    B.

     Isobaric process

    C.

     Hyperbolic process

    D.

     All of these


  15. The thermodynamic difference between a Rankine cycle working with saturated steam and the Carnot cycle is that

  16. A.

     Carnot cycle can't work with saturated steam

    B.

     Heat is supplied to water at temperature below the maximum temperature of the cycle

    C.

     A Rankine cycle receives heat at two places

    D.

     Rankine cycle is hypothetical


  17. A process, in which the gas is heated or expanded in such a way that the product of its pressure and volume remains constant, is called

  18. A.

     Isothermal process

    B.

     Hyperbolic process

    C.

     Adiabatic process

    D.

     Polytropic process


  19. The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is

  20. A.

     Equal to one

    B.

     Less than one

    C.

     Greater than one

    D.

     None of these