Explore topic-wise MCQs in GATE (Mechanical Engineering).

This section includes 261 Mcqs, each offering curated multiple-choice questions to sharpen your GATE (Mechanical Engineering) knowledge and support exam preparation. Choose a topic below to get started.

251.

The maximum temperature in the I.C. engine cylinder is of the order of

A. 500- 1000°C
B. 1000- 1500°C
C. 1500-2000°C
D. 2000-2500°C
Answer» E.
252.

In a typical medium speed 4-stroke cycle diesel engine the inlet valve

A. opens at 20° before top dead center and closes at 35° after the bottom dead center
B. opens at top dead center and closes at bottom dead center
C. opens at 10° after top dead center and closes 20° before the bottom dead center
D. may open or close anywhere
Answer» B. opens at top dead center and closes at bottom dead center
253.

In case of gas turbines, the gaseous fuel consumption guarantees are based on

A. high heat value
B. low heat value
C. net calorific value
D. middle heat value
Answer» C. net calorific value
254.

If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the %age increase in efficiency will be

A. 2%
B. 4%
C. 8%
D. 14%
Answer» E.
255.

All heat engines utilize

A. low heat value of oil
B. high heat value of oil
C. net claorific value of oil
D. calorific value of fuel
Answer» B. high heat value of oil
256.

If the intake air temperature of I.C. engine increases, its efficiency wil

A. increase
B. decrease
C. remain same
D. unpredictable
Answer» C. remain same
257.

The calorific value of gaseous fuels is expressed in terms of

A. kcal
B. kcal/kg
C. kcal/m2
D. kcal/n?
Answer» E.
258.

The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called

A. net efficiency
B. efficiency ratio
C. relative efficiency
D. overall efficiency
Answer» D. overall efficiency
259.

Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged ?

A. yes
B. no
C. to some extent
D. unpredictable
Answer» C. to some extent
260.

Supercharging is the process of

A. supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
B. providing forced cooling air
C. injecting excess fuel for raising more load
D. supplying compressed air to remove combustion products fully
Answer» B. providing forced cooling air
261.

The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

A. 1/2
B. 1
C. 2
D. 4
Answer» D. 4