MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
If the ratio of the length of connecting rod to crank radius increases, then |
| A. | primary unbalanced force increases |
| B. | primary unbalanced force decreases |
| C. | secondary unbalanced force increases |
| D. | secondary unbalanced force decreases |
| Answer» E. | |
| 2. |
In order to balance the reciprocating masses:- |
| A. | primary and secondary forces must be balanced |
| B. | primary couple must be balanced |
| C. | secondary couple must be balanced |
| D. | All options are correct |
| Answer» E. | |
| 3. |
Hammer blow in reciprocating engine varies with: |
| A. | Rotational speed |
| B. | (Rotational speed)2 |
| C. | (Rotational speed)1/2 |
| D. | (Rotational speed)3 |
| Answer» C. (Rotational speed)1/2 | |
| 4. |
A vertical single-cylinder opposed piston type engine has reciprocating parts of mass 2000 kg for the lower piston and 2750 kg for the upper piston. The lower piston has a stroke of 60 cm and the engine is in primary balance. If the ratio of the length of connecting rod to crank is 4 for the lower piston and 8 for the upper piston, and when the crankshaft speed is of 135 r.p.m., the maximum secondary unbalanced force will be |
| A. | 48935.5 N |
| B. | 46946.5 N |
| C. | 44968.5 N |
| D. | 42989.5 N |
| Answer» D. 42989.5 N | |
| 5. |
A two-cylinder in-line engine with identical cylinders has cranks at 180° to each other. When the engine runs, the unbalanced forces are |
| A. | both the primary and secondary forces |
| B. | only the secondary force |
| C. | only the primary force |
| D. | Both forces are balanced |
| Answer» C. only the primary force | |
| 6. |
A system of masses rotating in different parallel planes is in dynamic balance. If the resultant |
| A. | Force is equal to zero |
| B. | Couple is equal to zero |
| C. | Force and the resultant couple both are equal to zero |
| D. | Force is numerically equal to the resultant couple but neither of them need necessarily be zero. |
| Answer» D. Force is numerically equal to the resultant couple but neither of them need necessarily be zero. | |
| 7. |
In reciprocating engines primary forces _________. |
| A. | Are completely balanced |
| B. | Are partially balanced |
| C. | Are balanced by secondary forces |
| D. | Cannot be balanced |
| Answer» C. Are balanced by secondary forces | |
| 8. |
A rigid body can be replaced by two masses placed at fixed distance apart. The two masses form an equivalent dynamic system, if (select the most appropriate answer). |
| A. | the sum of the two masses is equal to the total mass of the body |
| B. | the centre of gravity of two masses coincide with that of the body |
| C. | the sum of the mass moment of inertia of the masses about their centre of gravity is equal to the mass moment inertia of the body |
| D. | All of the above |
| Answer» E. | |
| 9. |
If there are several unbalanced masses in a rotor in different planes, the minimum number of balancing masses required is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 10. |
A rotating disc of 1 m diameter has two eccentric masses of 0.5 kg each at radii of 50 mm and 60 mm at the angular positions of 0 degree and 150 degree respectively. A balancing mass of 0.1 kg is to be used to balance the rotor. What is the radial position of the balancing mass? |
| A. | 50 mm |
| B. | 120 mm |
| C. | 150 mm |
| D. | 280 mm |
| Answer» D. 280 mm | |
| 11. |
In order to facilitate the starting of the locomotive in any position, the cranks of a locomotive with two cylinders are placed at the following angle to each other _________. |
| A. | 45° |
| B. | 90° |
| C. | 135° |
| D. | 180° |
| Answer» C. 135° | |