251. The ideal efficiency of simple gas turbine cycle depends on________________
A. pressure ratio
B. maximum cycle temperature
C. minimum cycle temperature
D. all of the above
E. none of the above

252. The material commonly used for air craft gas turbine is__________________?
A. stainless steel
B. high alloy’ steel
C. duralumin
D. Timken, Haste and Inconel allpys
E. titanium

253. The maximum combustion pressure in gas turbine as compared to I.C. engine is_________________?
A. more
B. less
C. same
D. depends on other factors
E. unpredictable

254. As the turbine inlet temperature increases, the thermal efficiency of gas turbine for the optimum pressure ratio_____________________?
A. increases
B. decreases
C. remains same
D. first increases and then decreases
E. first decreases and then increases

255. It is not possible to use closed gas turbine cycle in aeronautical engines because_________________ ?
A. it is inefficient
B. it is bulky
C. it requires cooling water for its operation
D. non of theses

256. For an irreversible gas turbine cycle, the efficiency and work ratio both depend on___________________?
A. pressure ratio alone
B. maximum cycle temperature alone
C. minimum cycle temperature alone
D. both pressure ratio and maximum cycle temperature
E. none of the above

257. Producer gas is produced by_____________________?
A. carbonization of coal
B. passing steam over incandescent coke
C. passing air and a large amount of steam over waste coal at about 65°C
D. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
E. same way as the natural gas

258. A gas turbine used in air craft should have______________________?
A. high h.p. and low weight
B. low weight and small frontal area
C. small frontal area and high h.p.
D. high speed and high h.p.
E. all of the above

259. The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the_____________________?
A. adiabatic temperature drop in the stage
B. total temperature drop
C. total temperature drop in the stage
D. total adiabaitc temperature drop
E. difference of maximum and minimum temperature in the cycle

260. The closed cycle in gas turbines_________________?
A. provides greater flexibility
B. provides lesser flexibility
C. in never used
D. is used when gas is to be burnt
E. none of the above

NOTE
IF YOU THINK ANY OF THE MCQ ABOVE IS WRONG.
PLEASE COMMENT WITH CORRECT ANSWER AND ITS DETAIL EXPLANATION IN COMMENT BOX.
THANK YOU