Question 53

The Correct Answer is D **Why option D ("supercharging") is correct:** Supercharging is the process of increasing the density of air entering the engine cylinders by compressing it to a pressure greater than atmospheric pressure. This allows more fuel to be efficiently burned in each combustion cycle, leading to increased power output and efficiency, which directly matches the definition provided in the question. The device used to achieve this is called a supercharger. **Why the other options are incorrect:** * **A) engine displacement:** Engine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine. It is a measurement of the engine's size, not the process of pressurizing the intake air. * **B) super-aspirating:** This is not a standard or correct engineering term for this process. While the process involves exceeding the natural aspiration (drawing in air at atmospheric pressure), the correct technical term is "supercharging." * **C) air injection:** Air injection, particularly in older systems, refers to forcing air into the exhaust stream (usually via an air pump) to aid in oxidizing unburned hydrocarbons in the catalytic converter or exhaust manifold for emissions control. It does not refer to pressurizing the intake air supplied to the cylinder for combustion.