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MCQOPTIONS
This section includes 513 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
A heat engine utilizes the |
| A. | Calorific value of oil |
| B. | Low heat value of |
| C. | High heat value of oil |
| D. | Mean heat value of oil |
| Answer» D. Mean heat value of oil | |
| 502. |
The object of supercharging the engine is |
| A. | To reduce mass of the engine per brake power |
| B. | To reduce space occupied by the engine |
| C. | To increase the power output of an engine when greater power is required |
| D. | All of the above |
| Answer» E. | |
| 503. |
In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the |
| A. | Beginning of suction stroke |
| B. | End of suction stroke |
| C. | Beginning of exhaust stroke |
| D. | End of exhaust stroke |
| Answer» B. End of suction stroke | |
| 504. |
The pressure and temperature at the end of compression stroke in a petrol engine are of the order of |
| A. | 4-6 kg/cm² and 200-250°C |
| B. | 6-12 kg/cm² and 250-350°C |
| C. | 12-20 kg/cm² and 350-450°C |
| D. | 20-30 kg/cm² and 450-500°C |
| Answer» C. 12-20 kg/cm¬¨‚⧠and 350-450¬¨‚àûC | |
| 505. |
In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to |
| A. | Prevent sparking across the gap between the points |
| B. | Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» D. None of the above | |
| 506. |
Scavenging air in diesel engine means |
| A. | Air used for combustion sent under pressure |
| B. | Forced air for cooling cylinder |
| C. | Burnt air containing products of combustion |
| D. | Air used for forcing burnt gases out of engine's cylinder during the exhaust period |
| Answer» E. | |
| 507. |
The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is |
| A. | More |
| B. | Less |
| C. | Same |
| D. | May be more or less depending on engine capacity |
| Answer» C. Same | |
| 508. |
The effective inhibitor of pre-ignition is |
| A. | Alcohol |
| B. | Water |
| C. | Lead |
| D. | None of these |
| Answer» C. Lead | |
| 509. |
If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be |
| A. | 2% |
| B. | 4% |
| C. | 8% |
| D. | 14% |
| Answer» E. | |
| 510. |
Crankcase explosion in I.C. engines usually occurs as |
| A. | First a mild explosion followed by a bi explosion |
| B. | First a big explosion followed by a mil explosion |
| C. | Both mild and big explosions occurs simultaneously |
| D. | Never occurs |
| Answer» B. First a big explosion followed by a mil explosion | |
| 511. |
The sensing element in the control system of nuclear reactors measures the _________ of the neutron flux in the reactor. |
| A. | Temperature |
| B. | Volume |
| C. | Density |
| D. | None of these |
| Answer» D. None of these | |
| 512. |
As a result of detonation in an I.C. engine, following parameter attains very high value |
| A. | Peak pressure |
| B. | Rate of rise of pressure |
| C. | Rate of rise of temperature |
| D. | Peak temperature |
| Answer» C. Rate of rise of temperature | |
| 513. |
By higher octane number of spark ignition fuel, it is meant that the fuel has |
| A. | Higher heating value |
| B. | Higher flash point |
| C. | Lower volatility |
| D. | Longer ignition delay |
| Answer» E. | |