Right Answer: A retarder in an automobile is a device that slows down the vehicle by using resistance or friction, typically without relying on the brakes. It helps in controlling speed, especially during downhill driving, and reduces wear on the braking system.
Right Answer: The purpose of a governor in a diesel engine is to regulate the engine's speed by controlling the amount of fuel injected based on the load and speed requirements.
Ques:- When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is such that it act as) In the backward direction on the front wheel and in the forward direction on the rear wheel.(b) In the forward direction on the front wheel and in the backward direction on the rear wheel.(c) In the backward direction on both the front and rear wheels.(d) In the backward direction on both the front and rear wheels.
Right Answer: Different types of sounds in bikes running on SI (Spark Ignition) engines are produced due to variations in engine design, exhaust systems, tuning, and the materials used in construction. Factors like engine displacement, compression ratio, and the presence of aftermarket modifications also contribute to the unique sound characteristics of each bike.
Right Answer: - **15B25**: A low-carbon steel with approximately 0.15% carbon and 0.25% manganese. It is often used for structural applications and has good weldability.
- **10B21**: A low-carbon boron steel with about 0.10% carbon and 0.20% manganese. It is known for its good hardenability and is used in applications requiring high strength.
- **SCM-415**: A chromium-molybdenum alloy steel with approximately 0.40% carbon, 0.80% chromium, and 0.25% molybdenum. It offers good toughness and strength, commonly used in automotive and machinery components.
- **16MnCr5**: A low-alloy steel with about 0.16% carbon, 1.0% manganese, and 0.5% chromium. It is used for case-hardening applications, providing good wear resistance and toughness.
Right Answer: Vertical type mufflers are used in highway trucks primarily to improve exhaust flow and reduce back pressure, which enhances engine performance and efficiency.
Right Answer: The perfect average fuel consumption for a motorbike typically ranges from 40 to 60 miles per gallon (mpg), depending on the model and riding conditions.
Right Answer: Mixing oil in the fuel of a four-stroke bike can damage the engine and negatively affect performance. Four-stroke engines are designed to use oil separately in the crankcase, and adding oil to the fuel can lead to improper combustion, increased smoke, and potential engine deposits or damage.
Right Answer: Back pressure in an engine refers to the resistance or pressure that exhaust gases encounter as they exit the engine and pass through the exhaust system. It can affect engine performance and efficiency.
Right Answer: The principle of hydraulic braking is based on Pascal's Law, which states that when pressure is applied to a confined fluid, it is transmitted equally in all directions. In a hydraulic braking system, when the brake pedal is pressed, it creates pressure in the brake fluid, which is then transmitted to the brake calipers or drums, causing the brake pads or shoes to clamp onto the brake discs or drums, slowing down or stopping the vehicle.
Right Answer: Petrol engines are generally less efficient and produce less torque compared to diesel engines, making them less suitable for heavy-duty applications that require high power and durability.
Right Answer: To design a blower for a motor, consider the following steps:
1. **Determine Requirements**: Identify the airflow rate (CFM) and pressure (static pressure) needed for the application.
2. **Select Blower Type**: Choose between centrifugal or positive displacement blowers based on the required airflow and pressure characteristics.
3. **Motor Selection**: Select a motor with appropriate horsepower and speed to match the blower's requirements.
4. **Sizing**: Calculate the blower size based on the airflow and pressure requirements, using manufacturer performance curves.
5. **Design Parameters**: Define dimensions, blade design, and materials based on the application and environment.
For connecting two blowers to a motor:
1. **Parallel Connection**: Connect both blowers in parallel to increase airflow while maintaining the same pressure.
2. **Series Connection**: Connect blowers in series to increase pressure while maintaining the same airflow.
Ensure the motor can handle the combined load of the blowers in either configuration.
Right Answer: Back compression in an engine refers to the pressure that builds up in the combustion chamber during the exhaust stroke, which can hinder the efficient expulsion of exhaust gases and affect engine performance.
Right Answer: Injector pressure in heavy vehicles typically ranges from 200 to 300 bar (approximately 2900 to 4350 psi), depending on the engine design and fuel system.
Right Answer: Recent developments in automobile engines include the increased use of hybrid and electric powertrains, advancements in turbocharging and direct fuel injection for improved efficiency, and the integration of artificial intelligence for better engine management and performance optimization.
Right Answer: The types of cooling systems in passenger cars are:
1. **Liquid Cooling System** - Uses a liquid coolant to absorb and dissipate heat.
2. **Air Cooling System** - Uses air to cool the engine, typically found in older or smaller engines.
3. **Evaporative Cooling System** - Uses the evaporation of a liquid to cool the engine, less common in modern cars.
Right Answer: The types of injection systems in cars are:
1. Port Fuel Injection (PFI)
2. Direct Fuel Injection (DFI)
3. Dual Injection (combination of PFI and DFI)
4. Carbureted Injection (less common in modern vehicles)
Right Answer: Pouring petrol into a diesel engine can cause severe damage. The engine may misfire, run poorly, or not start at all, as diesel engines rely on the higher compression of diesel fuel for ignition. This can lead to engine knocking, damage to fuel injectors, and potential failure of the engine components.
