McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
Chapters
| 101. |
The choke is closed when the engine is |
| A. | accelerating |
| B. | hot |
| C. | cold |
| D. | idling |
| Answer» C. cold | |
| 102. |
Lean air mixture is required during |
| A. | idling |
| B. | starting |
| C. | accelerating |
| D. | cruising |
| Answer» D. cruising | |
| 103. |
The limits of air-fuel for SI engine are |
| A. | 8/1 to 18/1 |
| B. | 8/1 to 50/1 |
| C. | 25/1 to 50/1 |
| D. | 50/1 to 100/1 |
| Answer» A. 8/1 to 18/1 | |
| 104. |
For maximum thermal efficiency, the fuel-air mixture in SI engines should be |
| A. | lean |
| B. | rich |
| C. | stoichiometric |
| D. | may be rich or lean |
| Answer» A. lean | |
| 105. |
During starting petrol engines require |
| A. | stoichiometric mixture |
| B. | lean mixture |
| C. | rich mixture |
| D. | any air-fuel ratio is alright |
| Answer» C. rich mixture | |
| 106. |
Economizer is used to provide enriched mixture during |
| A. | Starling |
| B. | idling |
| C. | cruising |
| D. | full throttle operation |
| Answer» D. full throttle operation | |
| 107. |
When the throttle is suddenly opened, the mixture of the simple carburetor tends to become |
| A. | rich |
| B. | lean |
| C. | stoichiometric |
| D. | not affected |
| Answer» B. lean | |
| 108. |
Precise petrol injection system is |
| A. | direct injection |
| B. | sequential injection |
| C. | throttle body injection |
| D. | port injection |
| Answer» C. throttle body injection | |
| 109. |
The choke in an automobile meant for supplying |
| A. | lean mixture |
| B. | rich mixture |
| C. | stoichiometric mixture |
| D. | weak mixture |
| Answer» B. rich mixture | |
| 110. |
Modern carburetors provide the correct quality of air-fuel mixture during |
| A. | starting |
| B. | idling |
| C. | cruising |
| D. | all conditions |
| Answer» D. all conditions | |
| 111. |
A simple carburetor supplies rich mixture during |
| A. | starting |
| B. | idling |
| C. | cruising |
| D. | accelerating |
| Answer» D. accelerating | |
| 112. |
Fuel injector is used for |
| A. | gas engines |
| B. | CI engines |
| C. | SI engines |
| D. | none of the above |
| Answer» B. CI engines | |
| 113. |
Advantage of air injection system is |
| A. | cheaper fuels can be used |
| B. | mep is high |
| C. | fine atomization and distribution of the fuel |
| D. | all of the above |
| Answer» D. all of the above | |
| 114. |
Commonly used injection system in automobiles is |
| A. | air injection |
| B. | solid injection |
| C. | combination of (a) and (b) |
| D. | none of the above |
| Answer» B. solid injection | |
| 115. |
Fuel injection pressure in solid injection system is around |
| A. | <10 bar |
| B. | 10-20 bar |
| C. | 30-50 bar |
| D. | 200-250 bar |
| Answer» D. 200-250 bar | |
| 116. |
Fuel filters do not use generally |
| A. | oil |
| B. | paper |
| C. | cloth |
| D. | felt |
| Answer» B. paper | |
| 117. |
Fuel is injected in a four-stroke CI engine |
| A. | at the end of suction stroke |
| B. | at the end of expansion stroke |
| C. | at the end of compression stroke |
| D. | at the end of exhaust stroke |
| Answer» C. at the end of compression stroke | |
| 118. |
Injection system in which the pump and the injector nozzle is combined in one housing is known as |
| A. | common rail system |
| B. | distributor system |
| C. | unit injector system |
| D. | individual pump and nozzle system |
| Answer» C. unit injector system | |
| 119. |
Main advantage of pintaux nozzle is |
| A. | better cold starting performance |
| B. | ability to distribute the fuel |
| C. | good penetration |
| D. | good atomization |
| Answer» A. better cold starting performance | |
| 120. |
the most accurate gasoline injection system is |
| A. | direct injection |
| B. | port injection |
| C. | throttle body injection |
| D. | manifold injection |
| Answer» B. port injection | |
| 121. |
Advantage of fuel injection in SI engine is |
| A. | low initial cost |
| B. | low maintenance requirements |
| C. | increased volumetric efficiency |
| D. | none of the above |
| Answer» C. increased volumetric efficiency | |
| 122. |
‘MPFI’ stands for |
| A. | Multi point fuel injection |
| B. | Multi port fuel injection |
| C. | Manifold point fuel injection |
| D. | Manifold port fuel injection |
| Answer» A. Multi point fuel injection | |
| 123. |
In carburetor, Choke is incorporated |
| A. | Before the venturi |
| B. | After the venturi |
| C. | In the venturi |
| D. | Any of the above |
| Answer» A. Before the venturi | |
| 124. |
The following factors affect the process of carburetion |
| A. | Engine speed |
| B. | The temperature of incoming air |
| C. | The volatility of fuel |
| D. | All of the above |
| Answer» D. All of the above | |
| 125. |
In MPFI _____ is used to spray fuel into engine. |
| A. | Engine vacuum |
| B. | Suction pressure of engine |
| C. | Electric pump |
| D. | None of the above |
| Answer» B. Suction pressure of engine | |
| 126. |
L-MPFI system uses |
| A. | port injection |
| B. | direct injection |
| C. | manifold injection |
| D. | throttle body injection |
| Answer» A. port injection | |
| 127. |
D-MPFI system uses |
| A. | port injection |
| B. | manifold injection |
| C. | direct injection |
| D. | throttle body injection |
| Answer» B. manifold injection | |
| 128. |
Common rail injection system uses injection pressures of the order |
| A. | 100-200 bar |
| B. | 200-400 bar |
| C. | 400-600 bar |
| D. | 1500 bar |
| Answer» D. 1500 bar | |
| 129. |
Continuous injection system usually has |
| A. | plunger pump |
| B. | rotary pump |
| C. | gear pump |
| D. | vane pump |
| Answer» B. rotary pump | |
| 130. |
The cold start injector |
| A. | maintain stoichiometric air-fuel ratio |
| B. | provides lean air-fuel ratio |
| C. | gives rich air-fuel ratio |
| D. | is not used for any of the above functions |
| Answer» C. gives rich air-fuel ratio | |
| 131. |
ECU is an electronic injection system used for |
| A. | calculating the appropriate injection timing |
| B. | meeting only certain operating conditions |
| C. | closing the injection valve only |
| D. | none of the above |
| Answer» A. calculating the appropriate injection timing | |
| 132. |
With EFI (ELECTRONIC FUEL INJECTION) of diesel engines |
| A. | sharp start and stop is not possible |
| B. | very high injection pressure can be obtained |
| C. | sudden cylinder cut-off is impossible |
| D. | diagnostic properties are poor |
| Answer» B. very high injection pressure can be obtained | |
| 133. |
EFI system can achieve |
| A. | proper injection timing |
| B. | proper injection quantity |
| C. | proper injection pressure |
| D. | all of the above |
| Answer» D. all of the above | |
| 134. |
The first vehicle in India equipped with MPFI system in Indian automobile industry |
| A. | Tata Indica |
| B. | Daewoo Matiz |
| C. | Maruti Alto |
| D. | Chevrolet spark |
| Answer» B. Daewoo Matiz | |
| 135. |
The fuel in diesel engine is normally injected at pressure of |
| A. | 5-10 kg/cm2 |
| B. | 20-25 kg/cm2 |
| C. | 60-80 kg/cm2 |
| D. | 90-130 kg/cm2 |
| Answer» D. 90-130 kg/cm2 | |
| 136. |
The specific fuel consumption per BHP hour for diesel engine is approximately |
| A. | 0.15 kg |
| B. | 0.2 kg |
| C. | 0.25 kg |
| D. | 0.3 kg |
| Answer» B. 0.2 kg | |
| 137. |
The specific fuel consumption per BH hour for a petrol engine is approximately |
| A. | 0.15 kg |
| B. | 0.2 kg |
| C. | 0.25 kg |
| D. | 0.3kg |
| Answer» C. 0.25 kg | |
| 138. |
The air-fuel ratio of the petrol engine is controlled by |
| A. | fuel pump |
| B. | governor |
| C. | injector |
| D. | carburettor |
| Answer» D. carburettor | |
| 139. |
Pour point of fuel oil is the |
| A. | minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame |
| B. | temperature at which it solidifies or congeals |
| C. | it catches fire without external aid |
| D. | indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off |
| Answer» B. temperature at which it solidifies or congeals | |
| 140. |
A 5 BHP engine running at full load would consume diesel of the order of |
| A. | 0.3 kg/hr |
| B. | 1 kg/hr |
| C. | 3 kg/hr |
| D. | 5 kg/hr |
| Answer» B. 1 kg/hr | |
| 141. |
The secondary winding of ignition coil consists of |
| A. | few turns of fine wire |
| B. | few turns of thick wire |
| C. | many turns of fine wire |
| D. | many turns of thick wire |
| Answer» C. many turns of fine wire | |
| 142. |
Dwell is the time |
| A. | for which the points remain closed |
| B. | for which the points remain open |
| C. | time during which inlet and exhaust valves are open |
| D. | none of the above |
| Answer» A. for which the points remain closed | |
| 143. |
Dwell period |
| A. | is directly proportional to engine speed |
| B. | is inversely proportional to engine speed |
| C. | does not depend on engine speed |
| D. | none of the above |
| Answer» B. is inversely proportional to engine speed | |
| 144. |
If the contact breaker gap is small, it results in |
| A. | advanced timing |
| B. | increased dwell |
| C. | rapid burning of the pointer gaps |
| D. | none of the above |
| Answer» C. rapid burning of the pointer gaps | |
| 145. |
For a four cylinder engine operating at N rpm, the contact breaker must make and break the circuit |
| A. | N times |
| B. | 2N times |
| C. | N/2 times |
| D. | none of the above |
| Answer» B. 2N times | |
| 146. |
Contact breaker should be set |
| A. | just before starting the engine |
| B. | before adjustment of dwell angle |
| C. | after adjustment of dwell angle |
| D. | before setting spark plug gap |
| Answer» C. after adjustment of dwell angle | |
| 147. |
Dwell meter is used for |
| A. | setting spark plug gap |
| B. | contact breaker gap |
| C. | setting the ignition advance |
| D. | setting |
| Answer» B. contact breaker gap | |
| 148. |
For a four cylinder vertical engine, the commonly used firing order is |
| A. | 1-2-3-4 |
| B. | 3-4-1-2 |
| C. | 1-3-4-2 |
| D. | 4-3-2-1 |
| Answer» C. 1-3-4-2 | |
| 149. |
For engine operating with rich mixtures the optimum spark timing |
| A. | must be advanced |
| B. | must be retarded |
| C. | must be at TDC |
| D. | none of the above |
| Answer» A. must be advanced | |
| 150. |
For peak lead operation, the spark advance |
| A. | must be decreased |
| B. | must be increased |
| C. | need not be altered |
| D. | none of the above |
| Answer» A. must be decreased | |
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