MCQOPTIONS
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MCQOPTIONS
This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Automobile Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
For a single cylinder reciprocating engine speed is 500 rpm, stroke is 150 mm, mass of reciprocating parts is 21 kg; mass of revolving parts is 15 kg at crank radius. If two-thirds of reciprocating masses and all the revolving masses are balanced, the mass at a radius of 150 mm will be |
| A. | 7.5 kg |
| B. | 10.5 kg |
| C. | 12.5 kg |
| D. | 14.5 kg |
| Answer» E. | |
| 2. |
A rotor weighing 2 kN is supported on bearings A and B which are 1 m apart. The centre of mass of the rotor is at a distance 0.4 m from bearing A. It is observed that there is an unbalanced couple of magnitude 300 N-m which leaves the shaft balanced statically. The dynamic reactions at the supports will be |
| A. | 800 N and 800 N |
| B. | 300 N and 800 N |
| C. | 800 N and -300 N |
| D. | 300 N and -300 N |
| Answer» E. | |
| 3. |
Consider a reciprocating engine with crank radius R and connecting rod of length L. The secondary unbalance force for this case is equivalent to primary unbalance force due to a virtual crank of _______. |
| A. | radius L/2 rotating at twice the engine speed |
| B. | radius R/4 rotating at half the engine speed |
| C. | radius \(\frac{L^2}{4R}\) rotating at half the engine speed |
| D. | radius \(\frac{R^2}{4L}\) rotating at twice the engine speed |
| Answer» E. | |
| 4. |
A mass m1 attached to a shaft at radius r1, rotating with angular velocity ω rad/s, can be balanced by another single mass m2 which is attached to the opposite side of the shaft at radius r2, in the same plane, if |
| A. | m1r2 = m2r1 |
| B. | m1r1 = m2r2 |
| C. | m1r1ω1 = m2r2ω2 |
| D. | m1r2ω1 = m2r1ω2 |
| Answer» C. m1r1ω1 = m2r2ω2 | |
| 5. |
In slider crank mechanism, secondary forces fluctuate at |
| A. | The rotating frequency |
| B. | Twice the rotating frequency |
| C. | Four times the rotating frequency |
| D. | Half the rotating frequency |
| Answer» C. Four times the rotating frequency | |
| 6. |
In order to have a complete balance of the several revolving masses in different planes |
| A. | the resultant force must be zero |
| B. | the resultant couple must be zero |
| C. | both the resultant force and couple must be zero |
| D. | none of these |
| Answer» D. none of these | |
| 7. |
A rigid rotor supported on two bearings which are 2.75m apart, is found to have an unbalanced couple of magnitude 300 N-m. The dynamic reactions at each bearing would be nearly |
| A. | 55 N |
| B. | 109 N |
| C. | 190 N |
| D. | 219 N |
| Answer» C. 190 N | |
| 8. |
In case of partial balancing of single cylinder reciprocating engine, what is the primary disturbing force along the line of stroke? |
| A. | cmrω2 cos θ |
| B. | (1 - c2) mrω2 cos θ |
| C. | (1 - c) mrω2 cos θ |
| D. | (1 - c) mr2ω cos 2θ |
| Answer» D. (1 - c) mr2ω cos 2θ | |