MCQOPTIONS
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MCQOPTIONS
This section includes 287 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
665×10-3m, calculate the critical speed of the shaft in rps. Centre of disc at 0.25m away from centre of axis of shaft. |
| A. | 8.64 |
| B. | 9.64 |
| C. | 10.64 |
| D. | 12.2 |
| Answer» E. | |
| 2. |
6 kN/m and the damping constant of the damper is 400 Ns/m. If the mass is 50 kg, then the damping factor (d ) and damped natural frequency (fn), respectively, are |
| A. | 0.471 and 1.19 hz |
| B. | 0.471 and 7.48 hz |
| C. | 0.666 and 1.35 hz |
| D. | 0.666 and 8.50 hz |
| Answer» B. 0.471 and 7.48 hz | |
| 3. |
6 x 10 = 6 rad/s. |
| A. | 2.055 m |
| B. | 3.055 m |
| C. | 4.055 m |
| D. | 5.055 m |
| Answer» B. 3.055 m | |
| 4. |
A disc is a spinning with an angular velocity ω rad/s about the axis of spin. The couple applied to the disc causing precession will be |
| A. | 1/2 iω2 |
| B. | iω2 |
| C. | 1/2 iωωp |
| D. | iωωp |
| Answer» E. | |
| 5. |
The axis of precession is to the plane in which the axis of spin is going to rotate. |
| A. | parallel |
| B. | perpendicular |
| C. | spiral |
| D. | none of the mentioned |
| Answer» C. spiral | |
| 6. |
A Watt’s governor is a spring loaded governor. |
| A. | true |
| B. | false |
| Answer» C. | |
| 7. |
A Watt’s governor can work satisfactorily at speeds from |
| A. | 60 to 80 r.p.m |
| B. | 80 to 100 r.p.m c) 100 to 200 r.p.m d) 200 to 300 r.p.m |
| Answer» B. 80 to 100 r.p.m c) 100 to 200 r.p.m d) 200 to 300 r.p.m | |
| 8. |
The ratio of height of Porter governor to the height of Watt’s governor is |
| A. | m/m + m |
| B. | m/ m + m |
| C. | m + m/m |
| D. | m + m/m |
| Answer» D. m + m/m | |
| 9. |
The height of a Watt’s governor is |
| A. | directly proportional to speed |
| B. | directly proportional to (speed) |
| C. | inversely proportional to speed |
| D. | inversely proportional to (speed) |
| Answer» E. | |
| 10. |
Isolation factor is twice the transmissibility ratio. |
| A. | true |
| B. | false |
| Answer» C. | |
| 11. |
Which of the following is true regarding Ɛ>1? |
| A. | transmitted force is greater than applied force |
| B. | transmitted force is less than applied force |
| C. | spring force is less than applied force |
| D. | damping force is less than applied force |
| Answer» B. transmitted force is less than applied force | |
| 12. |
If isolation factor is negative, then what is the phase difference between transmitted and disturbing force? |
| A. | 180° |
| B. | 90° |
| C. | 450° |
| D. | 360° |
| Answer» B. 90° | |
| 13. |
Which of the following is a type of transmitted force to the foundation? |
| A. | damping force |
| B. | undamping force |
| C. | tensile force |
| D. | torsional force |
| Answer» B. undamping force | |
| 14. |
When a periodic disturbing force is applied to a machine, the force is transmitted to the foundation by the means of spring. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 15. |
In a slider crank mechanism, the length of the crank and connecting rod are 180 mm and 540 mm respectively. The crank position is 45° from inner dead centre. The crank shaft speed is 450 r.p.m. (clockwise), calculate angular velocity of the connecting rod in rad/s. |
| A. | 10.3 |
| B. | 11.1 |
| C. | 12.2 |
| D. | 11.8 |
| Answer» C. 12.2 | |
| 16. |
While calculating angular acceleration of the connecting rod, sin2(θ) term is neglected. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 17. |
Which of the following expression represent the angular acceleration α of the connecting rod? |
| A. | −ω2 . sin θ/n |
| B. | −ω2 . cos θ.n |
| C. | ω2. cos θ/n |
| D. | ω2 . sin θ.n |
| Answer» B. −ω2 . cos θ.n | |
| 18. |
5 m/s. |
| A. | 4.19 |
| B. | 5 |
| C. | 3.49 |
| D. | 3.36 |
| Answer» D. 3.36 | |
| 19. |
The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon = gearth/6) is |
| A. | ωn |
| B. | 0.408ωn |
| C. | 0.204ωn d) 0.167ωn |
| Answer» B. 0.408ωn | |
| 20. |
The first critical speed of an automobile running on a sinusoidal road is calculated by (modeling it as a single degree of freedom system) |
| A. | resonance |
| B. | approximation |
| C. | superposition |
| D. | rayleigh quotient |
| Answer» B. approximation | |
| 21. |
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be |
| A. | less than unity |
| B. | equal to unity |
| C. | greater than unity |
| D. | zero |
| Answer» D. zero | |
| 22. |
What is not the effect of unbalanced forces? |
| A. | load on bearings |
| B. | dangerous vibrations |
| C. | stresses in various members |
| D. | violation of conservation of mass principle |
| Answer» E. | |
| 23. |
In a revolving rotor, the centrifugal force remains balanced as long as the centre of the mass of the rotor lies |
| A. | below the axis of shaft |
| B. | on the axis of the shaft |
| C. | above the axis of shaft |
| D. | away from the axis of shaft |
| Answer» C. above the axis of shaft | |
| 24. |
Balancing of single rotating mass by balancing masses in same plane and in different planes cannot take place. |
| A. | true |
| B. | false |
| Answer» C. | |
| 25. |
3 BALANCING MACHINES-FIELD BALANCING OF DISCS AND ROTORS. |
| A. | centripetal forces |
| B. | centrifugal forces |
| C. | friction forces |
| D. | inertia forces |
| Answer» E. | |
| 26. |
4 strokes engine have a lower thermal efficiency than 2 stroke engine. |
| A. | true |
| B. | false |
| Answer» C. | |
| 27. |
Compression stroke results in |
| A. | formation of negative loop |
| B. | formation of positive loop |
| C. | formation of an infinite loop |
| D. | formation of no loop |
| Answer» B. formation of positive loop | |
| 28. |
A negative loop is formed in the turning moment diagram because the pressure inside the cylinder is than the atmospheric pressure. |
| A. | equal |
| B. | more |
| C. | less |
| D. | no pressure inside |
| Answer» D. no pressure inside | |
| 29. |
Work produced by the 4-stroke engine is less because |
| A. | one power stroke per 2 revolutions |
| B. | one power stroke per revolution |
| C. | one power stroke per 4 revolution |
| D. | four power stroke per revolution |
| Answer» B. one power stroke per revolution | |
| 30. |
Centre of masses of the system lies on the axis of rotation. |
| A. | 1, 2, 3 and 4 |
| B. | 1, 2, and 3 only |
| C. | 2, 3 and 4 only |
| D. | 1, 3 and 4 only |
| Answer» E. | |
| 31. |
Which of the following displacement diagrams should be chosen for better dynamic performance of a cam-follower mechanism ? |
| A. | simple hormonic motion |
| B. | parabolic motion |
| C. | cycloidal motion |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 32. |
Ofset is provided to a cam follower mechanism to |
| A. | minimise the side thrust |
| B. | accelerate |
| C. | avoid jerk |
| D. | none of the mentioned |
| Answer» B. accelerate | |
| 33. |
The cam follower extensively used in air- craft engines is |
| A. | knife edge follower |
| B. | flat faced follower |
| C. | spherical faced follower |
| D. | roller follower |
| Answer» E. | |
| 34. |
If the stroke punch is 100mm, find the radius of the crank in mm. |
| A. | 200 |
| B. | 100 |
| C. | 50 d) 400 |
| Answer» D. | |
| 35. |
The balance energy required for punching is supplied by the flywheel by |
| A. | increase in its kinetic energy |
| B. | decrease in its kinetic energy |
| C. | decrease in its potential energy |
| D. | by variation of mass |
| Answer» C. decrease in its potential energy | |
| 36. |
When the length of the connecting rod is unknown then the value (θ2 –θ1)/2π is equal to |
| A. | t/s |
| B. | t/2s |
| C. | t/2r |
| D. | t/r |
| Answer» C. t/2r | |
| 37. |
Energy during actual punching operation is same as the energy supplied by the motor. |
| A. | true |
| B. | false |
| Answer» C. | |
| 38. |
The relation between stroke punch s and radius of crank r is |
| A. | s=r |
| B. | s=2r |
| C. | s=4r |
| D. | s=r/2 |
| Answer» C. s=4r | |
| 39. |
A machine punching 38 mm holes in 32 mm thick plate requires 7 N-m of energy per sq. mm of sheared area, find the maximum shear force required. |
| A. | 26.7 kn |
| B. | 53.4 kn c) 13.35 kn d) 106.8 kn |
| Answer» B. 53.4 kn c) 13.35 kn d) 106.8 kn | |
| 40. |
In a punching press, load is 0 at the time of punching. |
| A. | true |
| B. | false |
| Answer» C. | |
| 41. |
The maximum shear force required for punching depends on |
| A. | sheared area |
| B. | length of the plate |
| C. | speed of the flywheel |
| D. | total load |
| Answer» B. length of the plate | |
| 42. |
In a punching press, which of the following quantity is constant? |
| A. | load |
| B. | torque |
| C. | angular velocity |
| D. | angle of rotation |
| Answer» C. angular velocity | |
| 43. |
For a 4 cylinder engine, when the pressure inside the cylinders exceeds the atmospheric pressure then. |
| A. | work is done by the gases |
| B. | work is done on the gases |
| C. | work is done on the piston wall |
| D. | work is done by the piston wall |
| Answer» B. work is done on the gases | |
| 44. |
In the turning moment diagram of a multicylinder engine, the work done during exhaust stroke is by |
| A. | the gases |
| B. | on the gases |
| C. | piston wall |
| D. | valve |
| Answer» C. piston wall | |
| 45. |
For a multicylinder engine, the coefficient of fluctuation of speed would vary with |
| A. | number of cylinders |
| B. | remains unaffected |
| C. | length of connecting rod |
| D. | input temperature |
| Answer» C. length of connecting rod | |
| 46. |
For the given data of an Internal combustion engine : Mass of parts = 180 kg bore = 175 mm, length of stroke = 200 mm, engine speed = 500 r.p.m., length of connecting rod = 400 mm and crank angle = 60° from T.D.C, find the inertia force. |
| A. | 17.56 n |
| B. | 19.2 n |
| C. | 18.53 n |
| D. | 18.00 n |
| Answer» D. 18.00 n | |
| 47. |
Multi cylinder engines are usually placed at an equal inclination to each other. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 48. |
2 m and the cylinder bore is 0.5 m. engine runs at 250 r.p.m & 30° from T.D.C. Find the piston effort. |
| A. | 32.4 kn |
| B. | 35.2 kn |
| C. | 37.3 kn d) 40.2 n |
| Answer» D. | |
| 49. |
45 N/mm2. The connecting rod length between centres is 1.2 m and the cylinder bore is 0.5 m. If the engine runs at 250 r.p.m. and if the effect of piston rod diameter is neglected, calculate the net load on piston. |
| A. | 88000 n |
| B. | 90560 n |
| C. | 78036 n |
| D. | 88357 n |
| Answer» E. | |
| 50. |
In a horizontal engine, the weight of the reciprocating parts also add/subtract to the piston effort. |
| A. | true |
| B. | false |
| Answer» C. | |