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
(D) none of the above
There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would__________________?
(A) remain same
(B) decrease
(C) increase
(D) unpredictable
(D) none of the above
The combustion efficiency of a gas turbine using perfect combustion chamber is of the order of________________?
(A) 50%
(B) 75%
(C) 85%
(D) 90%
(D) 99%
Water gas is produced by ___________________ ?
(A) carbonisation 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 caol, eke, anthractie coal or charcoal in a mixed air steam blast
(D) same way as the natural gas
The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio_____________________?
(A) increases
(B) decreases
(C) first increases and then decreases
(D) first decreases and then increases
(D) remains same
The following is true for an open cycle gas turbine having exhaust heat exchanger. Atmospheric air before entering the compressor is____________________?
(A) heated
(B) compressed air before entering the combustion chamber is heated
(C) bled gas from turbine is heated and readmitted for complete expansion
(D) exhaust gases drive the compressor
(D) part of exhaust gases are heated and mixed up with atmospheric air to utilise exhaust heat
In jet engines, for the efficient production of large power, fuel is burnt in an atmosphere of__________________?
(A) vacuum
(B) atmospheric air
(C) compressed air
(D) oxygen alone
(D) liquid hydrogen
In gas turbines^ high thermal efficiency is obtained in_________________?
(A) closed cycle
(B) open cycle
(C) both of the above
(D) closed/open depending on other con-siderations
(D) unpredictable
A closed gas turbine in which fuel is burnt directly in the air is not possible because of__________________?
(A) high pressure ratio
(B) increasing gas temperature
(C) high specific volume
(D) high friction losses
(D) paucity of 02
In the axial flow gas turbine, the work ratio is the ratio of____________________?
(A) compressor work and turbine work
(B) output and input
(C) actual total head tempeature drop to the isentrpic total head drop from total head inlet to static head outlet
(D) actual compressor work and theoretical comprssor work
(D) none of the above