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MCQOPTIONS
This section includes 2670 Mcqs, each offering curated multiple-choice questions to sharpen your Railways knowledge and support exam preparation. Choose a topic below to get started.
| 1151. |
The molecular weight of vinyl chloride is 62.5 Thus the molecular weight of a polyvinyl chloride with a degree of polymerisation of 20000 is: |
| A. | \[\frac{20000}{62.5}\] |
| B. | \[\frac{62.5}{20000}\] |
| C. | \[62.5\times 20000\] |
| D. | 20000 |
| Answer» D. 20000 | |
| 1152. |
Tempering of quenched maritensitic steel is necessary to improve the: |
| A. | Hardness of the metal |
| B. | Surface texture of the metal |
| C. | Corrosion resistance of the metal |
| D. | Ductility of the metal. |
| Answer» E. | |
| 1153. |
The alloy steel designated as 40 Cr 18 Ni 2 by Bureau of Indian Standards contains: |
| A. | 0.4% C, 18% Cr and 2% Ni |
| B. | 4.0% C, 1.8% Cr and 0.2% Ni |
| C. | 0.4% C, 1.8% Cr and 0.2% Ni |
| D. | 0.4% C, 1.8% Cr and 0.2 % Ni. |
| Answer» B. 4.0% C, 1.8% Cr and 0.2% Ni | |
| 1154. |
Which of the following statement is true about brittle fracture? |
| A. | High temperature and low strain rates favour brittle fracture |
| B. | Many metal with HCP crystal structure commonly show brittle fracture |
| C. | Brittle fracture is always preceded by noise |
| D. | Cup and cone formation is characteristic for brittle materials. |
| Answer» C. Brittle fracture is always preceded by noise | |
| 1155. |
Herbert cloudburst hardness test is conducted to know: |
| A. | Uniformity of hardness over a surface |
| B. | Softness of non-metallic components |
| C. | Hardness of non-metallic components |
| D. | Hardness at specified depth inside the surface |
| Answer» B. Softness of non-metallic components | |
| 1156. |
Dye penetrant method is generally used to locate: |
| A. | Core defects |
| B. | surface defects |
| C. | Superficial defects |
| D. | temporary defects. |
| Answer» C. Superficial defects | |
| 1157. |
Which of the following metal shrinks most from molten state to solid state? |
| A. | Cast iron |
| B. | cast steel |
| C. | Brass |
| D. | admiralty metal |
| Answer» C. Brass | |
| 1158. |
Which of the following generally decreases in the steel after quench-hardening 1. Brittleness 2. Percentage elongation 3. Impact strength |
| A. | 1 and 2 only |
| B. | 2 and 3 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» C. 1 and 3 only | |
| 1159. |
In aircraft, air-refrigeration cycle is used because of: |
| A. | Low unit weight per tonne of refrigeration |
| B. | High heat transfer rate |
| C. | Lower temperature at high-altitudes |
| D. | Higher coefficient of performance |
| Answer» B. High heat transfer rate | |
| 1160. |
Waste heat can be effectively used in which one of the following refrigeration system? |
| A. | Vapour compression cycle |
| B. | Vapour absorption cycle |
| C. | Air refrigeration cycle |
| D. | Vortex refrigeration system |
| Answer» C. Air refrigeration cycle | |
| 1161. |
A condenser of refrigeration system rejects heat at rate of 120 kW. While its compressor consumes a power of 30 kW. The coefficient of performance of the system would be: |
| A. | 1/4 |
| B. | 44256 |
| C. | 3 |
| D. | 4 |
| Answer» E. | |
| 1162. |
Match List-I (Basic components of Aqua ammonia refrigeration system) with List-II functions of the components in the system and select the correct answer using the codes given below the lists: List-I List-II A. Generator 1. Dehydration B. Analyser 2. Removal of vapour from strong aqua - ammonia solution C. Rectifier 3. Producing dry ammonia vapour by removing traces for water particles completely D. Receiver 4. Storage of high pressure liquid ammonia 5. Formation of liquid ammonia from high pressure vapours. Codes: |
| A. | A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]5 |
| B. | A\[\to \]5, B\[\to \]3, C\[\to \]4, D\[\to \]2 |
| C. | A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]5 |
| D. | A\[\to \]2, B\[\to \]1, C\[\to \]3, D\[\to \]4 |
| Answer» E. | |
| 1163. |
Consider the following factors: (1) Wind velocity (2) Type of a activity (3) Indoor design conditions (4) Door openings Occupancy load in cooling load calculation depends upon: |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 1 and 4 |
| D. | 2 and 3 |
| Answer» E. | |
| 1164. |
If the specific heats of dry air and water vapour are \[1.00\,\,\text{kJ/kg}-K\] and \[1.88\,\,\text{kJ/kg}-K\] respectively and the humidity ratio is 0.011, then the specific heat of moist air at \[25{}^\circ C.\] and 50% relative humidity will be |
| A. | \[1.0207\,\,\text{kJ/kg}-K\] |
| B. | \[1.869\,\,\text{kJ/kg}-K\] |
| C. | \[1.891\,\,\text{kJ/kg}-K\] |
| D. | \[0.9793\,\,\text{kJ/kg}-K\] |
| Answer» B. \[1.869\,\,\text{kJ/kg}-K\] | |
| 1165. |
The atmosphere air at dry bulb temperature of \[15{}^\circ C\] enters a heating coil maintained at \[40{}^\circ C.\] The air leaves the heating coil at \[25{}^\circ C.\] The bypass factor of the heating coil is: |
| A. | 0.376 |
| B. | 0.476 |
| C. | 0.6 |
| D. | 0.67 |
| Answer» D. 0.67 | |
| 1166. |
When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than its dry bulb temperature, then the air is said to be: |
| A. | Cooled and humidified |
| B. | Cooled and dehumidified |
| C. | Heated and humidified |
| D. | Heated and dehumidified |
| Answer» B. Cooled and dehumidified | |
| 1167. |
Which of the following statements are correct? 1. The human body can lose heat even if temperature. Is less than the atmospheric temperature. 2. Relative humidity can be increased by cooling dehumidification. 3. Warm air increases the rate of radiation of heat from the human body. 4. Increase in air movement increases the evaporation from the human body. Select the correct answer using the codes given below: |
| A. | 1 and 4 |
| B. | 2 and 4 |
| C. | 1 and 3 |
| D. | 2 and 3 |
| Answer» B. 2 and 4 | |
| 1168. |
The equivalent diameter D of a circular duct corresponding to a rectangular duct having longer side ?a? and shorter side 'b' the same velocity and Pressure drop is given by: |
| A. | \[D=\frac{a+b}{ab}\] |
| B. | \[D=\frac{ab}{a+b}\] |
| C. | \[D=\frac{\left( a+b \right)}{2ab}\] |
| D. | \[D=\frac{2ab}{a+b}\] |
| Answer» E. | |
| 1169. |
Consider the following steps: (1) Starting of compressor. (2) Starting of cooling tower pump (3) Starting of chiller water pump (4) Starting of blower motor of cooling coil The correct sequence of these steps in the starting of a central air conditioning plant using chilled water cooling coil is: |
| A. | 3, 1, 4, 2 |
| B. | 1, 3, 2, 4 |
| C. | 3, 2, 1, 4 |
| D. | 1, 3, 4, 2 |
| Answer» D. 1, 3, 4, 2 | |
| 1170. |
The coefficient of performance (COP) of a refrigerator working as a heat pump is given by: |
| A. | \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}+2\] |
| B. | \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}+1\] |
| C. | \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}-1\] |
| D. | \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}\] |
| Answer» C. \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}-1\] | |
| 1171. |
In a domestic refrigerator, a capillary tube controls the flow of refrigerant form the: |
| A. | Expansion valve to the evaporator |
| B. | Evaporator to the thermostat |
| C. | Condenser to the expansion valve |
| D. | Condenser to the evaporator |
| Answer» E. | |
| 1172. |
In a variable speed S.I. Engine, the maximum torque occurs at the maximum: |
| A. | Speed |
| B. | Brake power |
| C. | Indicated power |
| D. | Volumetric efficiency |
| Answer» D. Volumetric efficiency | |
| 1173. |
Divided chamber diesel engines use lower injection pressures compared to open chamber engines because: |
| A. | Pintle nozzles cannot withstand high injection pressures |
| B. | High air swirl does not require high injection pressures for atomization |
| C. | High injection pressures may cause over penetration |
| D. | High injection pressure causes leakage of the fuel at the pintle |
| Answer» C. High injection pressures may cause over penetration | |
| 1174. |
Velocity of flame propagation in the SI engine is maximum for a fuel-air mixture which is: |
| A. | 10% richer than stocihiometric |
| B. | Equal to stoichiometric |
| C. | More than 10% richer than stocihiometric |
| D. | 10% leaner than stoichiometric |
| Answer» B. Equal to stoichiometric | |
| 1175. |
Consider the following emission of an IC engine: (1) CO (2) HC (3) \[N{{O}_{X}}\] (4) Particulates Which of these emissions cause photochemical smog? |
| A. | 1 and 4 |
| B. | 1 and 2 |
| C. | 2 and 3 |
| D. | 3 and 4 |
| Answer» D. 3 and 4 | |
| 1176. |
The effective jet exit velocity from a rocket is 2700 m/s. The forward flight velocity is 1350 m/s. the propulsive efficiency of the unit is: |
| A. | 200% |
| B. | 100% |
| C. | 66.666% |
| D. | 33.333% |
| Answer» D. 33.333% | |
| 1177. |
Consider the following statements: In a turbojet engine, thrust may be increased by: 1. Increasing the jet velocity 2. Increasing the mass flow rate of air. 3. After burning of the fuel. Of these statements: |
| A. | 1 and 2 are correct |
| B. | 2 and 3 are correct |
| C. | 1 and 3 are correct |
| D. | 1, 2 and 3 are correct |
| Answer» B. 2 and 3 are correct | |
| 1178. |
Consider the following statements: The thrust of rocket engine depends upon: 1. Effective jet velocity 2. Weight of the rocket 3. Rate of propellant consumption Of these statements: |
| A. | 1 and 2 are correct |
| B. | 1 and 3 are correct |
| C. | 2 and 3 are correct |
| D. | 1, 2 and 3 are correct |
| Answer» C. 2 and 3 are correct | |
| 1179. |
Which one of the following is the correct sequence of the position of the given components in a turboprop? |
| A. | Propeller, Compressor, Turbine, Burner |
| B. | Compressor, Propeller, Burner, Turbine |
| C. | Propeller, Compressor, Burner, Turbine |
| D. | Compressor, propeller. Turbine, Burner |
| Answer» D. Compressor, propeller. Turbine, Burner | |
| 1180. |
Which of the following pairs of engine and performance/characteristic is/are correctly matched? 1. Turbojet: Efficiency increases with flight speed 2. SI engine: Lowest specific fuel consumption 3. Turboprop: Suitable for low flight speeds Select the correct answer using the codes given below: Codes: |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 1 and 3 |
| D. | 2 alone |
| Answer» D. 2 alone | |
| 1181. |
In some carburettors, meter rod and economizer device is used for: |
| A. | Cold starting |
| B. | idling |
| C. | Power enrichment |
| D. | acceleration |
| Answer» C. Power enrichment | |
| 1182. |
The object of providing masked inlet valve in the air passage of compression-ignition engines is to |
| A. | Enhance flow late |
| B. | Control air flow |
| C. | Induce primary swirl |
| D. | Induce secondary turbulence |
| Answer» B. Control air flow | |
| 1183. |
Match List I with List II and select the correct answer using the codes given below the lists: List-I (Name of propellant) List-II (Type of propellant) A. Nitric acid 1. Fuel B. Hydrogen 2. Monopropellant C. Fuming nitric acid hydrazine 3. Oxidizer D. Methyl nitrate-methyl alcohol 4. Compounded liquid mono propellant 5. Hypergolic propellant Codes: |
| A. | A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]5 |
| B. | A\[\to \]1, B\[\to \]2, C\[\to \]5, D\[\to \]4 |
| C. | A\[\to \]3, B\[\to \]1, C\[\to \]5, D\[\to \]4 |
| D. | A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]5 |
| Answer» D. A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]5 | |
| 1184. |
Suppose, the mean body surface temperature of a certain unclothed person is \[30{}^\circ C,\] the mean temperature of surrounding surfaces is \[21{}^\circ C\] and the air within the room is at \[32{}^\circ C,\] 90 per cent RH, then the person will lose maximum body heat by: |
| A. | Convection |
| B. | Radiation |
| C. | Mass transfer |
| D. | Convection, radiation mass transfer |
| Answer» E. | |
| 1185. |
Which of the following are the assumptions involved in the auto-ignition theory put forth for the onset of knock in SI engines? 1. Flame velocity is normal before the onset of auto ignition. 2. A number of end-gas elements auto ignite simultaneously. 3. Preflame reactions are responsible for preparing the end-gas to ignite. Select the correct answer using the codes given below: |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 2 and 3 |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 1186. |
In summer air-conditioning, the conditioned air passing through the space undergoes a process of: |
| A. | Sensible cooling |
| B. | Sensible heating |
| C. | Cooling and dehumidification |
| D. | Heating and humidification |
| Answer» C. Cooling and dehumidification | |
| 1187. |
Consider the following statements about a rocket engine: 1. It is a very simple in construction and operation. 2. It can attain very high vehicle velocity. 3. It can operate for very long duration. Of these statements: |
| A. | 1 and 3 are correct |
| B. | 1 and 2 are correct |
| C. | 2 and 3 are correct |
| D. | 1, 2 and 3 are correct |
| Answer» C. 2 and 3 are correct | |
| 1188. |
Consider the following statements: 1. Volumetric efficiency of diesel engines is higher than that of SI engines 2. When a SI engine is throttled; its mechanical efficiency decreases. 3. Specific fuel consumption increases as the power capacity of the engine increases. 4. Inspite of higher compression ratios, the exhaust temperature in diesel engines is much lower than that in SI engines. Of these statements: |
| A. | 1, 2, 3 and 4 are correct |
| B. | 1, 2 and 3 are correct |
| C. | 3 and 4 are correct |
| D. | 1, 2 and 4 are correct |
| Answer» B. 1, 2 and 3 are correct | |
| 1189. |
A sample of moist air is at a temperature T and relative humidity 50%. A part of the moisture is removed adiabatically by using an absorbent. If the heat of adsorption is negligible, the resulting air will have the same: |
| A. | Dry bulb temperature but a lower wet bulb temperature |
| B. | Wet bulb temperature but a higher dry bulb temperature |
| C. | Dry bulb temperature but a higher dry bulb temperature |
| D. | Wet bulb temperature but a lower dry bulb temperature |
| Answer» D. Wet bulb temperature but a lower dry bulb temperature | |
| 1190. |
The pipes and fittings in an ammonia refrigeration system should be made of: |
| A. | Cast street or wrought iron |
| B. | Aluminum |
| C. | Naval brass |
| D. | Copper |
| Answer» B. Aluminum | |
| 1191. |
Consider the following statements: Detonation in the S.I. engine can be suppressed by 1. Retarding the spark timing 2. Increasing the engine speed. 3. Using 10% rich mixture. Of these statements: |
| A. | 1 and 3 are correct |
| B. | 2 and 3 are correct |
| C. | 1, 2 and 3 are correct |
| D. | 1 and 2 are correct |
| Answer» E. | |
| 1192. |
In a SI Engine, which one of the following is the correct order of the fuels with increasing detonation tendency? |
| A. | Paraffins, Olefins, Naphthenes, Aeromatics |
| B. | Aeromatics, Naphthenes, Paraffins, Olefins |
| C. | Naphthenes, Olefins, Aeromatics, Paraffins |
| D. | Aeromatics, Naphthenes, Olefins, Paraffins |
| Answer» E. | |
| 1193. |
For same power output and same compression ratio, as compared to two-stroke engines, four-stroke S.I. engines have: |
| A. | Higher fuel consumption |
| B. | Lower thermal efficiency |
| C. | Higher exhaust temperatures |
| D. | Higher thermal efficiency |
| Answer» E. | |
| 1194. |
A two-stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two-stroke engine will: |
| A. | Be twice that of the four-stroke engine |
| B. | Be half that of the four-stroke engine |
| C. | Be the same as that of the four-stroke |
| D. | Depend upon whether it is a C.I. or S.I. engine |
| Answer» D. Depend upon whether it is a C.I. or S.I. engine | |
| 1195. |
For maximum specific output of a constant volume cycle (Otto cycle): |
| A. | The working fluid should he air |
| B. | The speed should he high |
| C. | Suction temperature should be high |
| D. | Temperature of the working fluid at the end of compression and expansion should be equal |
| Answer» B. The speed should he high | |
| 1196. |
The presence of nitrogen in the products of combustion ensures that: |
| A. | Complete combustion of fuel takes place |
| B. | Incomplete combustion of fuel occurs |
| C. | Dry products of combustion are analysed |
| D. | Air is used for the combustion |
| Answer» E. | |
| 1197. |
Which of the following factors are responsible formation of \[N{{O}_{X}}\] in spark ignition engine combustion: 1. Incomplete combustion 2. High temperature 3. Availability of answer. |
| A. | 2 and 3 |
| B. | 1 and 2 |
| C. | 1 and 3 |
| D. | 1, 2 and 3 |
| Answer» B. 1 and 2 | |
| 1198. |
Items given in List I and List II pertain to gas analysis. Match List I with List II and select the correct answer. List-I List-II A. \[C{{O}_{2}}\] 1. Alkaline pyrogallol B. Orsat apparatus 2. KOH solution C. CO 3. Wet analysis D. \[{{O}_{2}}\] 4. Ammonia-calcurprous chloride 5. Dry analysis Codes: |
| A. | A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 |
| B. | A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]4 |
| C. | A\[\to \]1, B\[\to \]5, C\[\to \]4, D\[\to \]2 |
| D. | A\[\to \]2, B\[\to \]5, C\[\to \]4, D\[\to \]1 |
| Answer» E. | |
| 1199. |
only rocket engines can be propelled to 'SPACE' because: |
| A. | They can generate very high thrust. |
| B. | They have high propulsion efficiency. |
| C. | These engines can work on several fuels. |
| D. | They are not air-breathing engines. |
| Answer» E. | |
| 1200. |
Consider the following statements relating to rocket engines: 1. The combustion chamber in a rocket engine is directly analogous to the reservoir of a supersonic wind tunnel. 2. Stagnation conditions exist at the combustion chamber. 3. The exit velocities of exhaust gases are much higher than those in jet engines. 4. Efficiency of rocket engines is higher than that of jet engines. Of these statements: |
| A. | 1, 3 and 4 are correct |
| B. | 1, 3 and 4 are correct |
| C. | 1, 2 and 3 are correct |
| D. | 1 and 4 are correct |
| Answer» D. 1 and 4 are correct | |