Vacuum for reciprocating steam engines compared to steam turbines is__________________?

Related Mcqs:

1. Expanding steam to a very low pressure (high vacuum) in steam engines is _________________?

   A. desirable
   B. economical
   C. essential
   D. optional
   E. uneconomical

2. Diesel engines as compared to petrol engines require ______________________?

   A. bigger flywheel
   B. smaller flywheel
   C. same size flywheel
   D. no flywheel
   E. flywheel whose size may be less or more depending on several other fac-tors

3. While steam expands in turbines, theoretically the entropy________________?

   A. remains constant
   B. increases
   C. decreases
   D. behaves unpredictably
   E. none of the above

4. One kg of steam sample contains 0.8 kg dry steam; it’s dryness fraction is__________________?

   A. 0.2
   B. 0.8
   C. 1.0
   D. 0.6
   E. 0.5

5. In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 mts and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is__________________?

   A. 40%
   B. 25%
   C. 50%
   D. 80%
   E. 90%

6. The change in internal energy in steam engines equals to__________________?

   A. work done during the rankine cycle ;
   B. work done during compression.
   C. work done during adiabatic expansion
   D. change in enthalpy
   E. none of the above

7. In ordetjo obtain superheated steam, a superheater is added in an existing boiler. As as result, furnace vacuum will _________________?

   A. remain unaffected
   B. improve C. worsen
   C. may improve/worsen depending on size
   D. unpredictable

8. Diesel engines have low specific fuel consumption compared to petrol engine. This statement is____________________?

   A. not true
   B. true at full load
   C. true at part load
   D. true at both part and full load
   E. there could not be any such criterion

9. Steam in water tube boiler as compared to fire tube boiler_________________?

   A. can be raised rapidly
   B. is raisd at slower rate
   C. is raised at same rate
   D. could be raised at fast/slow rate depending on design
   E. none of the above is true

10. The pressure of reheat steam after passing through reheater compared to inlet condition is _________________?

    A. more
    B. less
    C. equal
    D. may be more or less depending on capacity of reheater
    E. none of the above