mechanical engineering MCQs – Page 9

Practise multiple-choice questions from mechanical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

mechanical engineering Mcqs

1. compressors gas turbines and jet engines 2. theory of machines 3. nuclear power plants 4. engineering materials 5. strength of materials mechanical engineering 6. thermodynamics 7. heat transfer 8. i c engines 9. steam boilers engines nozzles and turbines 10. engineering mechanics 11. fluid mechanics mechanical engineering 12. production technology 13. machine design 14. hydraulic machines 15. workshop technology 16. refrigeration and air conditioning

161. In jet propulsion power unit, the inlet duct of diverging shape is used in order to _______________ ?
0

A. provide robust structure

B. convert kinetic energy of air into pres-sure energy

C. collect more air

D. beautify the shape

E. none of the above

162. In air breathing jet engine, the jet is formed by expanding__________________?
0

A. liquid

B. plasma

C. highly heated atmospheric air

D. gases

E. solids

163. The discharge through a reaction turbine with increase in unit speed____________________?
0

A. first decreases and then increases

B. remains unaffected

C. increases

D. decreases

E. first increases and then decreases

164. If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water would discharge_____________________?
0

A. 1.5 Q

B. 0.75 Q

C. same quantity of liquid

D. Q/0.75

E. none of the above

165. The nuclear energy is measured as__________________?
0

A. curie

B. MeV

C. farads

D. kWhr

E. MW

166. A nuclear unit becoming critical means_______________?
0

A. it is generating power to rated capacity

B. it generates no heat

C. chain reaction that causes automatic splitting of the fuel nuclei has been established

D. there is danger of nuclear spread

E. it is capable of generating much more than rated capacity

167. Centrifugal pump is started with its delivery valve __________________?
0

A. irrespective of any position

B. kept fully open

C. kept 50% open

D. kept fully closed

E. none of the above

168. Mechanical efficiency of gas turbines as compared to I.C engines is____________________?
0

A. same

B. higher

C. unpredictable

D. depends on on odier considerations

E. lower

169. The power available for take off and climb in case of turbojet engine as compared to reciprocating engine is ___________________?
0

A. less

B. may be less or more depending on ambient conditons

C. same

D. unpredictable

E. more

170. U238 will undergo fission by_________________?
0

A. low energy (slow) neutrons alone

B. medium energy neutrons

C. either fast or slow neutrons

D. none of the above

E. high energy (fast) neutrons alone

171. Losses in a centrifugal compressor are due to__________________?
0

A. impeller channel losses

B. all of the above

C. diffuser losses

D. inlet losses

E. none of the above

172. In a compressor, free air delivered is the actual volume delivered at the stated pressure reduced to ____________________?
0

A. 20C and 1 kg/cm2

B. N.T.P. conditions

C. 0C and 1 kg/cm2

D. intake temperature and pressure conditions

E. none of the above

173. The efficiency of a centrifugal pump is maximum when its blades are__________________?
0

A. bent forward

B. bent forward first and then backward

C. straight

D. bent backward

E. bent backward first and then forward

174. The combustion efficiency of a gas turbine using perfect combustion chamber is of the order of________________?
0

A. 85%

B. 99%

C. 50%

D. 90%

E. 75%

175. The jnaximum combustion pressure in gas turbine as compared to I.C. engine is_________________?
0

A. less

B. unpredictable

C. more

D. depends on other factors

E. same

176. Air vessels in reciprocating pump are used to__________________?
0

A. save pump from cavitation

B. smoothen flow

C. reduce acceleration to minimum

D. increase pump efficiency

E. increase pump head

177. The shrinkage allowance for cast iron pattern is________________?
0

A. 20 mm/m

B. 10 mm/m

C. 15 mm/m

D. 26 mm/m

178. Casting of a centrifugal pump is designed so as to minimize________________?
0

A. loss of kinetic energy

B. cavitation

C. friction loss

D. starting time

E. static head

179. For slow-speed large capacity compressor, following type of valve will be best suited________________?
0

A. any of the above

B. mechanical valve of the corliss, sleeve, rotary or semirotary type

C. disc or feather type

D. poppet valve

E. none of the above

180. The energy required to be applied to a radioactive nucleus for the emission of a neutron is________________?
0

A. 20 MeV

B. 1 MeV

C. 4.3 MeV

D. 7.8 MeV

E. 2.4 MeV

Previous Next

Showing 161 to 180 of 4266 mcqs