Q1: Which of the following is normally not found in both the S.I. (petrol) & C.I. (diesel) engines ?

ANS:B - Fuel injector

The component that is normally not found in both S.I. (petrol) and C.I. (diesel) engines is the Fuel injector. Explanation:

1. Air filter: Both petrol (S.I.) and diesel (C.I.) engines require an air filter to ensure that clean air is supplied to the combustion chamber for efficient combustion. Therefore, air filters are commonly found in both types of engines.
2. Fuel injector: In petrol (S.I.) engines, fuel is typically mixed with air before entering the combustion chamber and is delivered by a carburetor or fuel injection system. However, in diesel (C.I.) engines, fuel is directly injected into the combustion chamber at high pressure using fuel injectors. Therefore, fuel injectors are specific to diesel engines and are not commonly found in petrol engines.
3. Exhaust silencer: Both petrol and diesel engines generate exhaust gases during the combustion process. Exhaust silencers, also known as mufflers, are used in both types of engines to reduce noise levels by attenuating the exhaust gas pulses.
4. Battery: Both petrol and diesel engines require a battery for starting purposes, providing electrical power for ignition systems, fuel injection systems (if applicable), lighting, and other electrical components. Therefore, batteries are commonly found in both types of engines.