Automobile and Mechanical Mock Test! Trivia Questions Quiz

The suspension system in a vehicle is responsible for absorbing vibration and impact forces from the road surface. This is important because it helps to provide a smoother and more comfortable ride for the passengers. By absorbing these forces, the suspension system also helps to protect other components of the vehicle, such as the tires and the chassis, from excessive wear and tear. Overall, the suspension system plays a crucial role in enhancing both the comfort and the safety of the vehicle.

Pre-ignition refers to the condition where the air-fuel mixture in an engine ignites before the spark plug ignites it. This can occur due to various reasons such as hot spots in the combustion chamber, carbon deposits, or incorrect ignition timing. Pre-ignition leads to an uncontrolled combustion process, causing knocking or pinging sounds, reduced engine performance, and potential damage to the engine components. It is important to address pre-ignition issues promptly to prevent engine damage and ensure optimal engine performance.

The correct answer is "opens at 20° before T.D.C. and closes at 35° after B.D.C." In a four-stroke Diesel engine, the intake valve opens before the piston reaches the top dead center (T.D.C.) to allow air/fuel mixture to enter the cylinder. It then closes after the piston reaches the bottom dead center (B.D.C.) to seal the cylinder and allow compression and combustion to occur. This timing ensures efficient intake and combustion processes in the engine.

Vapor locking in a brake system occurs when the brake fluid becomes overheated due to frequent brake application. When the fluid gets too hot, it can form vapor bubbles, which can compress and cause a loss of brake pressure. This can result in a spongy or unresponsive brake pedal, making it difficult to stop the vehicle effectively. Therefore, overheating of the fluid due to frequent brake application is the condition that causes vapor locking in a brake system.

Rocker arms are used to transfer the motion of the cam to the valves in an engine. The camshaft rotates and pushes against the rocker arms, which in turn push the valve stems to open and close the valves. This allows the intake and exhaust gases to flow in and out of the combustion chamber at the appropriate times, ensuring proper engine performance. Pistons are not involved in this process, as they are responsible for converting the energy from the combustion process into mechanical motion. The camshaft pulley is also not directly involved in transferring motion to the valves; its main function is to synchronize the rotation of the camshaft with other engine components.

The most effective method of controlling S.I. engine exhaust emissions is by using a catalytic converter. A catalytic converter is a device that is installed in the exhaust system of a vehicle and helps to reduce harmful emissions such as carbon monoxide, nitrogen oxides, and hydrocarbons. It works by using catalysts to facilitate chemical reactions that convert these pollutants into less harmful substances before they are released into the atmosphere. This technology has been widely adopted in modern vehicles as it significantly helps in reducing air pollution and improving air quality.

A broach is a cutting tool used to create precision holes or shapes in materials. It typically has different types of teeth to perform various operations. Roughing teeth are used to remove a large amount of material quickly, semi-finishing teeth are used to remove smaller amounts of material and provide a smoother finish, and finishing teeth are used for the final pass to achieve a high level of accuracy and surface finish. Therefore, a broach typically has all of these types of teeth to perform different stages of the machining process.

The overall efficiency of a reaction turbine is defined as the ratio of the power produced by the turbine to the energy actually supplied by the turbine. This means that it measures how effectively the turbine converts the energy input into useful power output. By comparing the power output to the energy input, the overall efficiency provides a measure of the turbine's performance and effectiveness in converting energy.

Judder during braking is caused as a result of brake disc run out. When the brake disc is not perfectly flat or has uneven thickness, it causes the brake pads to make uneven contact with the disc during braking. This uneven contact leads to vibrations or judder felt through the steering wheel or brake pedal. It can also cause the vehicle to shake or jerk during braking, affecting the overall braking performance and safety.

Cast iron is a brittle material that is prone to forming segmental chips during machining. This is because cast iron has a high carbon content and a graphite structure, which causes the material to break into small, segmented pieces when it is subjected to cutting forces. On the other hand, mild steel, high speed steel, and high carbon steel are less likely to form segmental chips during machining.

The Kaplan turbine is preferred for a head of water ranging from 0 to 25 meters. This is because the Kaplan turbine is specifically designed to operate efficiently in low head applications. It has adjustable blades that can be rotated to match the flow and head conditions, allowing it to maximize power output in this range. The Pelton wheel is more suitable for high head applications, while the Francis turbine is better suited for medium head applications.

Mild steel has maximum ductility compared to copper, nickel, and aluminum. Ductility refers to the ability of a material to deform under tensile stress without fracturing. Mild steel is known for its high ductility, which means it can be easily stretched or drawn into wires without breaking. Copper, nickel, and aluminum also have good ductility, but mild steel surpasses them in terms of maximum ductility.

The included angle refers to the angle formed by the camber and S.A.I (Steering Axis Inclination). Camber is the inward or outward tilt of the wheels, while S.A.I is the angle between the steering axis and a vertical line. Both camber and S.A.I affect the stability and handling of the vehicle. Therefore, the correct answer is camber and S.A.I.

If the air-fuel mixture in a spark-ignition engine is too rich, it means that there is an excess of fuel compared to the amount of air. A rich mixture has a higher fuel-to-air ratio, which means that there is more fuel relative to the amount of air. Among the given options, an air-fuel ratio of 10:1 indicates a rich mixture, as there is a higher proportion of fuel compared to air.

Adding pigment to paint serves the purpose of giving color and a filling up effect to the paint. Pigments are finely ground particles that provide the desired hue and opacity to the paint. They are responsible for giving the paint its characteristic color and covering power. Additionally, pigments can also contribute to the overall texture and consistency of the paint, enhancing its filling up effect when applied to a surface. Therefore, the addition of pigment is crucial for achieving the desired color and visual appearance in paint.

The correct sequence for the given processes is stress relief, recrystallisation, and then grain growth. Stress relief is the first step where the internal stresses in the material are reduced. This is followed by recrystallisation, where new grains form and replace the deformed grains. Finally, grain growth occurs where the newly formed grains grow in size.

Tempering is the heat treatment process used for softening hardened steel. During tempering, the hardened steel is heated to a specific temperature and then cooled down slowly. This process reduces the hardness of the steel while improving its toughness and ductility. It involves the formation of fine carbide particles within the steel matrix, which helps to relieve internal stresses and increase the steel's ability to withstand impact and deformation. Therefore, tempering is the correct answer for softening hardened steel.

The conical locator is the most suitable choice when the diameter of the hole is subject to considerable variation. This type of locator has a tapered shape that allows it to fit into holes of different sizes. It can provide a secure and accurate location for jigs and fixtures, even when there is variability in the hole diameter. The conical shape helps to center the workpiece and maintain its position, ensuring precise and consistent results.

A Kaplan turbine runner is a type of turbine used in hydroelectric power plants. It is known for its adjustable blades, which allow for efficient operation across a wide range of flow rates. The number of blades in a Kaplan turbine runner is generally between 4 to 8. This range allows for optimal performance and balance between power output and turbine efficiency. Having a higher number of blades can increase the turbine's efficiency, but it also increases the complexity and cost of manufacturing. Therefore, the range of 4 to 8 blades is commonly used in Kaplan turbines.

The purpose of transmission in an automobile is to vary the speed of the automobile. The transmission system allows the driver to change gears and adjust the speed of the vehicle according to the road conditions and desired speed. By selecting different gear ratios, the transmission can increase or decrease the speed of the automobile, allowing it to operate efficiently at different speeds. The transmission also helps in providing the appropriate power and torque to the wheels, but its primary function is to vary the speed of the automobile.