mechanical engineering MCQs – Page 17

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 Review each marked answer and report any item that may be outdated or unclear.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

321. According to Lamis theorem___________________?
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A. three forces acting at a point will be in equilibrium

B. ection by the sides of a triangle, taken in order, they will be in equilibrium

C. if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

D. none of the above

E. three forces acting at a point can be represented by a triangle, each side being proportional to force

F. if three forces acting upon a particle are represented in magnitude and

322. In heat exchangers, degree of approach is defined as the difference between temperatures of________________?
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A. hot medium outlet and cold water outlet

B. hot medium inlet and outlet

C. cold water inlet and outlet

D. none of the above

E. hot medium outlet and cold water inlet

323. The fuel needed, with reflector in nuclear power plant, in order to generate sufficient neutrons to sustain a chain reaction, would be________________?
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A. same

B. zero

C. more

D. less

E. negative, i.e. fuel would be generated

324. When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by ___________________?
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A. conduction

B. conduction and convection

C. convection and radiation

D. convection

E. radiation

325. Uranium-233 is produced__________________?
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A. as basic raw material

B. artificially

C. by neutron irradiation of thorium

D. in high capacity furnaces

E. by neutron irradiation of Uz

326. Heat transfer takes place as per ________________?
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A. first law of thermodynamic

B. Kirchoffs law E. Stefans law

C. second law of the thermodynamics

D. zeroth law of thermodynamics

327. Two plates spaced 150 mm apart are maintained at 1000C and 70C. The heat transfer will take place mainly by ___________________?
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A. forced convection

B. radiation

C. free convection

D. radiation and convection

E. convection

328. Pick up the wrong statement ?
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A. axial flow compressors have instability region of operation

B. axial flow compressors are more stable than centrifugal type compressors but not as efficient

C. axial flow compressors have high capacity and efficiency

D. large gas turbines employ axial flow compressors

E. centrifugal compressors are used mainly on low flow pressure ratio gas turbines

329. Angle of friction is the_______________________?
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A. the ratio of minimum friction force to the friction force acting when the body is just about to move

B. ratio of static and dynamic friction

C. the ratio of minimum friction force to friction force acting when the body is in motion

D. angle between normal reaction and the resultant of normal reaction and the limiting friction

E. ratio of limiting friction and normal reaction

330. Pick up the correct statement?
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A. gas turbine uses same working fluid over and over again

B. closed cycle gas turbine is an I.C engine

C. ideal efficiency of closed cycle gas turbine plant is more than carnot cycle efficiency

D. thrust in turbo-jet is produced by nozzle exit gases

E. air-fuel ratio in a gas turbine is 100 : 1

331. The concept of overall coefficient of heat transfer is used in case of heat transfer by________________?
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A. convection

B. convection and radiation

C. conduction

D. radiation

E. conduction and convection

332. A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t2 (t 4), the acceleration of the particle will be given by the equation __________________?
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A. 6f-8

B. 6f-4

C. 3t2+2t

D. 3t2-lt

E. 6t2-8t

333. Half life of a radioactive isotope corresponds to the time required for half of the following to decay__________________?
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A. nulceus

B. electrons

C. neutrons

D. protons

E. atom

334. Thermal conductivity of a material may be defined as the________________?
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A. quantity of heat flowing in one second through one cm cube of material when opposite faces ^re maintained at a temperature difference of 1C

B. none of the above

C. quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1C

D. heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces

E. all of the above

335. Coulomb friction is the friction between _________________?
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A. solids and liquids

B. two lubricated surfaces

C. bodies having relative motion

D. two dry surfaces

E. electrically charged particles

336. The energy distribution of an ideal reflector at higher temperatures is largely in the range of ___________________?
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A. wavelength has nothing to do with it

B. none of the above

C. longer wavelength