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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 | |