MCQOPTIONS
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MCQOPTIONS
This section includes 471 Mcqs, each offering curated multiple-choice questions to sharpen your Uncategorized topics knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The combustion chamber of S.I. Engine should have progressively reduced volume of charge from point of igintion |
| A. | to increase rate of combustion |
| B. | to improve power output |
| C. | to reduce pressure rise of end gases |
| D. | none of the above |
| Answer» D. none of the above | |
| 152. |
Combustion chambers of SI engines are developed into hemispherical shapes since |
| A. | it has better appearance |
| B. | reduce length of flame travel |
| C. | reduces heat losses |
| D. | both b and c |
| Answer» E. | |
| 153. |
Detonation and Knocking in SI engine can be controlled by |
| A. | retarding the spark timing |
| B. | reduction in speed |
| C. | increase in surface to volume ratio |
| D. | none of the above |
| Answer» B. reduction in speed | |
| 154. |
Which factor in the design of combustion chamber to avoid knocking and detonation in SI engine is not applicable |
| A. | long flame travel |
| B. | exhaust valves away from end gas |
| C. | cooling of exhaust valve |
| D. | small bore |
| Answer» B. exhaust valves away from end gas | |
| 155. |
the most accurate method of determining friction power is by |
| A. | willins line |
| B. | morse test |
| C. | motoring test |
| D. | measurement of brake and indicated power |
| Answer» E. | |
| 156. |
A well designed combustion chamber of petrol engine is the one which has |
| A. | low volumetric efficiency |
| B. | high compression ratio |
| C. | high thermal output and efficiency |
| D. | none of the above |
| Answer» D. none of the above | |
| 157. |
T-head combustion chambers used by ford in the past are not suitable for modern SI engines because |
| A. | needs two cam shafts to operate each valve |
| B. | has long flame travel |
| C. | high surface to volume ratio |
| D. | all of the above |
| Answer» E. | |
| 158. |
what would be the mean effective pressure of the engine if the area of the indicator diagram is 13 cm2 , length of the indicator diagram is of 6cm and spring constant 2.9 bar/cm |
| A. | 6.5bar |
| B. | 5.8bar |
| C. | 3.5bar |
| D. | 7.8bar |
| Answer» C. 3.5bar | |
| 159. |
which of the following is performed for supercharging of ic engine |
| A. | roots blower |
| B. | axial compressor |
| C. | sliding vane type compressor |
| D. | reciprocationg compressor |
| Answer» C. sliding vane type compressor | |
| 160. |
what would be the mean effective pressure of the engine if the area of the positive loop of the indicator diagram is of 5.75 squr cm, area of negative loop of the indicator diagram 0.25 squre cm and the length of the indicator diagrma is of 5.5cm |
| A. | 4bar |
| B. | 3bar |
| C. | 7bar |
| D. | 2bar |
| Answer» B. 3bar | |
| 161. |
In an eight cylinder engine the fuel suplied was 4000kg in 2 hours and the out put is 8000KW. Its bsfc is about |
| A. | 0.5kg/kwh |
| B. | 1kg/kwh |
| C. | 0.25kg/kwh |
| D. | 0.125kg/kwh |
| Answer» D. 0.125kg/kwh | |
| 162. |
Increasing cooling water temperature in SI engines, kncocking tendency_____ |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | cant predict |
| Answer» B. decreases | |
| 163. |
the more accurate dynamometer is |
| A. | prony brake type |
| B. | hydraulic type prony |
| C. | swinging field type |
| D. | eddy current type |
| Answer» B. hydraulic type prony | |
| 164. |
the most commonly used dynamometer on account of its simplicity of construction is the |
| A. | brake type |
| B. | hydraulic type prony |
| C. | swinging field type |
| D. | eddy current type |
| Answer» B. hydraulic type prony | |
| 165. |
The important factors which significantly affects process of carburetion are |
| A. | time available for preparation of mixture |
| B. | the temperature of exhaust gases in the exhaust manifold |
| C. | design of the induction system and combustion chamber |
| D. | both a and d |
| Answer» E. | |
| 166. |
brake mean effective pressure in an engine depends upon its |
| A. | speed only |
| B. | torque only |
| C. | speed and torque |
| D. | speed and power |
| Answer» C. speed and torque | |
| 167. |
brake thermal efficiecny of si engine usually varies between |
| A. | 25-30% |
| B. | 30-60% |
| C. | 60-80% |
| D. | more then 80% |
| Answer» B. 30-60% | |
| 168. |
the total power developed by the combustion of the fuel is |
| A. | bp |
| B. | ip |
| C. | fp |
| D. | none of the above |
| Answer» C. fp | |
| 169. |
heat balance sheet indicates |
| A. | amount of heat energy consumed in the combustion chamber |
| B. | brake up of the total energy input in to different parts |
| C. | amount of energy lost through the exhaust |
| D. | all of the above |
| Answer» C. amount of energy lost through the exhaust | |
| 170. |
mean effective pressure is the pressure |
| A. | pressure acting on the crank shaft |
| B. | which is acting on the piston through out the power stroke |
| C. | pressure required to inject the fuel in the combustion chamber |
| D. | none of the above |
| Answer» C. pressure required to inject the fuel in the combustion chamber | |
| 171. |
increasing the power out put by increasing the compression ratio is limited by |
| A. | weight to power ratio |
| B. | utilization of energy in fuel |
| C. | air fuel ratio |
| D. | hucr |
| Answer» E. | |
| 172. |
power out put of an engine can be increased by |
| A. | speed |
| B. | charge density |
| C. | compression ratio |
| D. | all of the above |
| Answer» E. | |
| 173. |
utilization of energy in exhaust gases causes power output to |
| A. | increases |
| B. | remains same |
| C. | decreases |
| D. | can not say |
| Answer» B. remains same | |
| 174. |
increase in charge density will |
| A. | increases volumetric efficiency |
| B. | power out put |
| C. | both a & b |
| D. | none of the above |
| Answer» D. none of the above | |
| 175. |
increase in speed to improve B.P is limited by |
| A. | maximum volumetric efficienccy |
| B. | robust engine |
| C. | fuel suply |
| D. | all of the above |
| Answer» E. | |
| 176. |
supercharging is a process of increasing the |
| A. | pressure in the cylinder |
| B. | suction pressure of charge |
| C. | temprature of the charge |
| D. | charge density |
| Answer» E. | |
| 177. |
supercharging is essential for |
| A. | stationary engine |
| B. | marine engine |
| C. | aircraft engine |
| D. | none of the above |
| Answer» D. none of the above | |
| 178. |
power out put of static engine at high alitude compared to power out put at sea level is |
| A. | higher |
| B. | lower |
| C. | same |
| D. | can not predict |
| Answer» E. | |
| 179. |
objective of superchargin are |
| A. | increase power output |
| B. | reduces weight to power ratio |
| C. | compansate loss of power at high altitudes |
| D. | all of the above |
| Answer» E. | |
| 180. |
which is not the objectve of supercharging |
| A. | to increase power out put |
| B. | to increase weight to power ratio |
| C. | to increase charge density at high alitude |
| D. | none of the above |
| Answer» C. to increase charge density at high alitude | |
| 181. |
endurance test for IC engine is conducted for |
| A. | 100hrs |
| B. | 200hrs |
| C. | 400hrs |
| D. | 500hrs |
| Answer» E. | |
| 182. |
mores test is conducted on |
| A. | single cylinder c.i engines |
| B. | multi cylinder engine |
| C. | vcc engine |
| D. | horizontle engine |
| Answer» C. vcc engine | |
| 183. |
four cylinder engine , the indicated power is 100KW and brake power is 20KW/cylinder . Its mechanical efficiency is about |
| A. | 0.2 |
| B. | 0.4 |
| C. | 0.8 |
| D. | none of the above |
| Answer» D. none of the above | |
| 184. |
If inlet temperature of air increases ___________ |
| A. | efficiency of ic engine increases but power output decreases |
| B. | efficiency of ic engine decreases but power output increases |
| C. | both efficiency and power output decrease |
| D. | both efficiency and power output increase |
| Answer» D. both efficiency and power output increase | |
| 185. |
the volumetric efficiecy of a well disigned engine is the |
| A. | 30-40% |
| B. | 40-60% |
| C. | 60-70% |
| D. | 75-90% |
| Answer» E. | |
| 186. |
if the brake power and indicated power of an engine are 22.286 KW and 56.589KW, what would be mecanicale efficiency of an engine ..? |
| A. | 0.75 |
| B. | 0.78 |
| C. | 0.79 |
| D. | 0.86 |
| Answer» E. | |
| 187. |
an engine develops 100 Kw wihing the cylinder using fuel having calrofic value of 40000kj/kg with brake thermal efficiency 0.24 and mechanical efficiency 0.8. the fuel consumprion in kg/s .? |
| A. | 30 |
| B. | 1/120 |
| C. | 0.3 |
| D. | 37.5 |
| Answer» B. 1/120 | |
| 188. |
an engine develops 12KW and frictional power is 4KW . The mechanical efficiency is about |
| A. | 0.67 |
| B. | 0.33 |
| C. | 0.75 |
| D. | none of the above |
| Answer» D. none of the above | |
| 189. |
a diesel engine consumes 5 grams fuel per second and develops a brake power 75KW. It has a mechanical efficiency of 85%. What would be the bsfc ? |
| A. | 0.055 g/kw s |
| B. | 0.033 g/kw s |
| C. | 0.066 g/kw s |
| D. | 0.088 g/kw s |
| Answer» D. 0.088 g/kw s | |
| 190. |
brke mean effective pressure and indicated mean effective pressure of an ic engine are 8br and 10 bar resp. the mechanical efficiency of an engine when runnign at 4000 rpm is |
| A. | 0.8 |
| B. | 1.25 |
| C. | 80 |
| D. | none of the above |
| Answer» B. 1.25 | |
| 191. |
A four cylinde si engine develops 100 kw running at a constant speed . When eginition of each cylinder is cut-off successively at the same speed , the BP is 71, 70, 71, 72 KW. The FP of engine and mechanical efficiency are |
| A. | 116kw, 51.3% |
| B. | 16kw, 86.2% |
| C. | 29kw, 77.5% |
| D. | none of the above |
| Answer» C. 29kw, 77.5% | |
| 192. |
Maximum pressure in SI engine is about |
| A. | 10 bar |
| B. | 70 bar |
| C. | 50 bar |
| D. | 30 bar |
| Answer» E. | |
| 193. |
what would be the brake power of the engine, if the net brake load on the engine is 1470 N, effective brake corcumeference is of 4m and engine runs at the speed of 233.33rpm |
| A. | 22.583kw |
| B. | 24.689kw |
| C. | 26.589kw |
| D. | none of theabove |
| Answer» D. none of theabove | |
| 194. |
For maximum economy mixture should be |
| A. | rich |
| B. | lean |
| C. | stoichiometric |
| D. | inert |
| Answer» C. stoichiometric | |
| 195. |
A:F ratio needed during maximum power is |
| A. | 12 to 13.5:1 |
| B. | 1970-01-01 15:01:00 |
| C. | 16 to 17.5:1 |
| D. | 18 to 20:1 |
| Answer» B. 1970-01-01 15:01:00 | |
| 196. |
During normal operating condition of engine load on engine shoud be |
| A. | 15% of rated load |
| B. | 90% of rated load |
| C. | 50% of rated load |
| D. | no load is applied |
| Answer» D. no load is applied | |
| 197. |
Favourable conditions for combustion are |
| A. | the presence of combustible mixture |
| B. | initiation by any means like spark plug is not required |
| C. | stabilization and propagation of flame in the combustion chamber |
| D. | both a and c |
| Answer» E. | |
| 198. |
Pressure during motoring in SI engine compared to CI engine is |
| A. | less |
| B. | more |
| C. | same |
| D. | none of the above |
| Answer» B. more | |
| 199. |
During idling of engine of engine, it requires |
| A. | lean fuel-air mixture |
| B. | no fuel in air |
| C. | stoichiometric air-fuel ratio |
| D. | rich mixture |
| Answer» E. | |
| 200. |
a six cylinder gasoline engine operates on the four stroke cycle . The bore of each cylinder is 80 mm and stroke is 100mm. What would be the compression ratio of the engine if clearnce volume per cylinder is 70cc |
| A. | 7.63 |
| B. | 8.18 |
| C. | 9.68 |
| D. | 5.28 |
| Answer» C. 9.68 | |