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NOZZLES MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

NOZZLES MULTIPLE

CHOICE QUESTIONS

(MCQ) WITH ANSWERS 

 

MCQ significantly increase the

understanding of the nozzle. More

MCQ will further increase the

knowledge about the nozzle. Nozzle

converts pressure energy into kinetic

energy. Nozzles are convergent,

divergent and convergent-divergent

types. There is velocity increase and

pressure decrease in a convergent nozzle.

There is velocity decrease and pressure

increase in a divergent nozzle.

1. The critical pressure ratio for initially wet steam across a steam nozzle is

  1. 546

  2. 582

  3. 578

  4. None

Ans: (ii)

2. The critical pressure ratio for initially super-heated steam across a steam nozzle is

  1. 582

  2. 546

  3. 578

  4. None

Ans: (ii)

     3. The efficiency of the nozzle is

  1. Actual enthalpy drop/Isotropic enthalpy drop

  2. Isobaric enthalpy drop/Isotropic enthalpy drop

  3. Iso-thermal enthalpy drop/Isotropic enthalpy drop

  4. None

Ans: (i)

     4. Velocity coefficient in a steam nozzle is

  1. (Iso-thermal enthalpy drop/Isotropic enthalpy drop)5

  2. (Actual enthalpy drop/Isotropic enthalpy drop)5

  3. (Isobaric enthalpy drop/Isotropic enthalpy drop)5

  4. None

Ans: (ii )

     5. Theoretical velocity at the exit of the nozzle will be

  1.  Exit velocity c2 = 44.42 (h1-h2)0.5

  2.  Velocity at exit c2 = 44.92 (h1-h2)0.5

  3.  c2 = 44.72 (h1-h2)0.5

  4.  None

Ans: (iii )

     6. The critical pressure ratio in a steam nozzle is equal to

  1. [(γ+1)/2](γ/(γ+1))

  2. [(2/(γ+1)] (γ/(γ+1))

  3. [(2/(γ+1)] ((γ+1)/γ)

  4. None

Ans: (ii)

     7. The equation for the shape of a nozzle is

  1.    Ratio dA/A =(dc/c)[M2 –1)

  2. dA/A =(dc/c)[1–M2)

  3. dA/A =(dc/c)[M2 +1)

  4. None

Ans: (i)

  1.  The velocity in a nozzle, When M = 1

  1. Minimum

  2. Maximum

  3. Neither minimum nor maximum

  4. None

Ans: (ii)

  1. When M = 1 the area of the nozzle be

  1. Minimum

  2. Maximum

  3. Neither minimum nor maximum

  4. None

Ans: (i)

  1. Using equation dA/A =(dc/c)[M2 –1) for a nozzle, when M<1 . Velocity in the nozzle will increase if the area of the nozzle

  1. Decreases

  2. Increases

  3. Constant

  4. (d) None

Ans:(i)

  1. With respect to equation dA/A =(dc/c)[M2 –1) for a nozzle, when M<1 . Velocity in the nozzle will decrease if the area of the nozzle

  1. Constant

  2. Increases

  3. Decreases

  4.  None

Ans:(ii)

  1. Using equation dA/A =(dc/c)[M2 –1) for a nozzle, when M>1 , velocity in the nozzle will increase if the area of the nozzle

  1. Increases

  2. Decreases

  3. Constant

  4. None

Ans:(i)

  1. Nozzle equation dA/A =(dc/c)[M2 –1), when M>1 , velocity in the nozzle will decrease if the area of the nozzle

  1. Decreases

  2. Increases

  3. Constant

  4. None

Ans:(i)

  1. Stagnation properties are used when the value of M is

  1. <0.1

  2. <0.4

  3. >0.4

  4. None

Ans: (iii)

  1. Efficiency of a nozzle vs efficiency of a diffuser is

  1. Less

  2. Equal

  3. More

  4. None

Ans: (iii)

  1. A nozzle is said to be choking under

  1. Minimum flow rate

  2. Maximum flow rate

  3. Neither maximum nor minimum flow rate

  4. None

Ans: (ii)

17. Velocity of steam in the divergent portion of the nozzle

  1. Remains constant

  2. Increases

  3. Decreases

  4. None

Ans: (ii)

  1. There is more friction in the

  1. convergent portion

  2. Divergent portion

  3. At the throat

  4. None

Ans: (ii)

  1. A steam nozzle is said to be choked if

  1. Steam flow through the nozzle decreases

  2. Pressure at throat is less than the exit pressure

  3. Pressure at throat is equal to the steam supply pressure

  4. None

Ans: (iv)

  1. Shock effect in a nozzle generally occurs in the

  1. Convergent portion

  2. At the exit

  3. Divergent portion

  4. None

Ans: (iii)

  1. Which type of nozzle is used in a steam turbine

  1. Convergent

  2. Divergent

  3. Convergent-divergent

  4. None

Ans: (iii)

  1. The velocity of steam at critical pressure at throat is

  1. More than the sound velocity

  2. Equal to the sound velocity

  3. Less than the velocity of sound

  4. None

Ans: (i)

  1. Steam leaves the nozzle with

  1. High pressure and high velocity

  2. Low pressure and low velocity

  3. High pressure and low velocity

  4. None

Ans: (iv)

  1. The condition of steam leaving the nozzle is

  1. Low pressure and high velocity

  2. Low pressure and low velocity

  3. High pressure and low velocity

  4. None

Ans: (i)

  1. Total friction in the nozzle is between the

  1. Inlet and exit

  2. Inlet and throat

  3. Throat and exit

  4. None

Ans: (iii)

  1. The action of steam turbine in the steam turbine is

  1. Static

  2. Dynamic

  3. Static as well as dynamic

  4. None

Ans: (ii)

     27. Critical velocity in a nozzle is given by the relation

  1. Critical velocity C* =(γRT*)5

  2. C* =(RT*/γ)5

  3. C* =(γR/T*)5

  4. None

Ans: (i)