Mechanical Engineering Mcqs

Gas turbine works on_______________?

(A) Brayton or Atkinson cycle

(B) Carnot cycle

(C) Rankine cycle

(D) Erricsson cycle

(D) Joule cycle

Submitted By: Ali Uppal


The pressure ratio of an ideal vaned compressor with increase in mass flow rate_________________?

(A) increases

(B) decreases

(C) remains constant

(D) first decreases and then increases

(D) unpredictable

Submitted By: Ali Uppal


Actual compression curve is___________________?

(A) same as isothermal

(B) same as adiabatic

(C) better than isothermal and adiabatic

(D) in between isothermal and adiabatic

(D) none of the above

Submitted By: Ali Uppal


The ratio of the increase in pressure in rotor blades to total increase in pressure in the stage is called__________________?

(A) pressure ratio

(B) pressure coefficient

(C) degree of reaction

(D) slip factor

(D) stage factor

Submitted By: Ali Uppal


Surging phenomenon in centrifugal com-pressor depends on ___________________?

(A) mass flow rate

(B) pressure ratio

(C) change in load

(D) stagnation pressure at the outlet

(D) all of the above

Submitted By: Ali Uppal


Gas turbines for power generaion are normally used___________________?

(A) to supply base load requirements

(B) to supply peak load requirements

(C) to enable start thermal power plant

(D) in emergency

(D) when other sources of power fail

Submitted By: Ali Uppal


Efficiency of gas turbine is increased by________________ ?

(A) reheating

(B) inter cooling

(C) adding a regenerator

(D) all of the above

(D) none of the above

Submitted By: Ali Uppal


The hottest point in a gas turbine is______________________?

(A) at the base

(B) at the tip

(C) in the center

(D) between ~ to i of the blade height

(D) uniformly heated

Submitted By: Ali Uppal


Temperature of gases at end of compression as compared to exhaust gases in a gas turbine is_________________?

(A) higher

(B) lower

(C) equal

(D) can’t be compared

(D) unpredictable

Submitted By: Ali Uppal


The pressure ratio in gas turbines is of the order of__________________?

(A) 2:l

(B) 4:1

(C) 61: 1

(D) 9 : 1

(D) 12:1.

Submitted By: Ali Uppal