Correct Answer - Option 4 : Fuel injector
Explanation:
| SI engine (Petrol Engine) |
CI engine (Diesel Engine) |
| Petrol is used as fuel. |
Diesel is used as fuel. |
| A petrol engine draws a mixture of petrol and air during the suction stroke. |
A diesel engine draws only air during the suction stroke. |
| The pressure at the end of the compression is about 10 kg/cm2. |
The pressure at the end of the compression is about 35 kg/cm2. |
| A spark plug is used |
Injector is used |
| The charge (i.e. petrol and air mixture) is ignited with the help of spark plug. |
The fuel is injected in the form of a fine spray. The temperature of the compressed air is about 600° C at a pressure of about 35 bars. |
| A carburetor is used to atomize, vaporize and meter the correct amount of fuel according to the requirement. |
Fuel injection pumps and atomizers are used to inject metered quantities of fuel at high pressure according to the requirement. |
| A petrol engine has a compression ratio of approximately from 6 to 10. |
A diesel engine has a compression ratio of approximately 15 to 25. |
| The combustion of fuel takes place approximately at a constant volume. In other words, it works on the Otto cycle. |
The combustion of fuel takes place approximately at constant pressure. in other words, it works on the Diesel cycle. |
| Less vibration, and hence, smooth running. |
More vibration, and hence, rough running and noisier. |
| Engine weight is less. |
Engine weight is more. |
| Small in size therefore less space occupied |
Large in size therefore more space occupied |
| It emits carbon monoxide. (CO) |
It emits carbon dioxide. (CO2) |
Exhaust silencer battery and fuel injector are parts of both Petrol and Diesel engines.
