Automotive Systems, Quiz Yourself 2

Explanation
External combustion engines, such as steam engines, work by burning fuel outside of the engine to produce heat. This heat is then transferred to a working fluid, usually water, which is converted into steam. The steam is then used to drive a turbine or a piston, which generates mechanical energy. In this process, a boiler is necessary to heat the working fluid and convert it into steam. Therefore, the correct answer is "boiler".

Explanation
Engines are devices that convert heat energy into mechanical energy. They achieve this through a series of processes such as combustion, expansion, and rotation of mechanical components. The mechanical energy produced by engines can be used to power various types of machinery, vehicles, or equipment. Therefore, the correct answer is "mechanical energy."

Explanation
When fuel is burned within an enclosed cylinder in an internal combustion engine, the expansion of gases creates pressure. This pressure pushes against the piston, causing it to move downward. As the piston moves, it transfers this motion to the crankshaft, which ultimately powers the vehicle or machine. Therefore, the correct answer is that the expansion of gases moves the piston downward.

Explanation
When the volume inside a cylinder decreases, the same amount of gas is compressed into a smaller space. This compression leads to an increase in the number of gas molecules colliding with the walls of the cylinder per unit time, resulting in an increase in pressure. Therefore, when the volume decreases, the pressure increases.

Explanation
As pressure increases inside the cylinder, the molecules are forced closer together, resulting in an increase in the average kinetic energy of the molecules. This increase in kinetic energy translates to an increase in temperature. Therefore, as pressure increases, the temperature also increases.

Explanation
The term "reciprocating" refers to a back-and-forth or to-and-fro motion. In the context of a piston, when it moves up and down within a cylinder, it exhibits a reciprocating motion. This motion is characterized by the piston alternating between two extreme positions, creating a repetitive or oscillating movement. Therefore, the correct answer is "reciprocating motion."

Explanation
Reciprocating motion is a back and forth movement along a straight line. Unlike circular motion, which follows a circular path, reciprocating motion involves oscillation in one direction and then back in the opposite direction, repeating the pattern. This type of motion can be observed in various mechanical systems, such as pistons in engines or the up and down motion of a seesaw. Therefore, the correct answer is "a straight line."

Explanation
Reciprocating motion refers to a back-and-forth or up-and-down movement, which is not suitable for turning the wheels of a vehicle. In order to turn the wheels, reciprocating motion needs to be converted into rotary motion, which is a circular movement around an axis. This allows the wheels to rotate and propel the vehicle forward. Therefore, the correct answer is rotary motion.

Explanation
Reciprocating motion refers to back-and-forth or linear motion, while rotary motion refers to circular motion. In order to convert reciprocating motion to rotary motion, a mechanism is needed to translate the linear motion into a circular one. The crankshaft and connecting rod system is commonly used for this purpose. The crankshaft converts the linear motion of the piston into rotational motion, while the connecting rod connects the piston to the crankshaft, allowing the transfer of motion. This mechanism is widely used in engines, where the reciprocating motion of the pistons is converted into rotary motion to drive the wheels or other mechanical components.

Explanation
Gasoline and diesel combustion engines require fuel, air, and ignition to operate. Fuel is necessary to provide the energy source for the engine, while air is needed for the combustion process. Ignition is essential to ignite the fuel-air mixture and initiate the combustion reaction. Without any of these three components, the engine would not be able to function properly and generate power.