Q-Bank : BAE MID-SEM - EngineerHub

Q1. GIVE CLASSIFICATION OF AUTOMOBILE ENGINE?

ANS : The classification of engine depends upon the types of Design, types of fuel used, number of strokes, number of cylinders, arrangement of cylinder, valve arrangement, type of colling etc.

1) Types of fuel used

Petrol engine: The engine which uses petrol for its working is called a petrol engine.
Diesel engine: The engine which uses diesel for its working is called a diesel engine.
Gas engine: An engine which using gas fuel for the working is called a gas engine.

2) Types of strokes

Two stroke engines: The engine in which the piston does two times motion i.e. one from TDC to BDC and other from BDC to TDC to produce a power stroke is called two stroke engines.
Four stroke engines: It is an engine in which the piston moves four times i.e.2 upward (form BDC to TDC) and 2 downward (from TDC to BDC) movement in one cycle of power stroke is called four stroke engines.

3) Types of Design

Rotary engine: In rotary engine, the rotor does rotary motion to produce power. There is no reciprocating motion. A rotor is present in the clamber which does rotary motion inside a clamber. Turbine engine is a type of rotary engine.
Reciprocating engine: in reciprocating engine, there is a piston and cylinder. due to the reciprocating motion within the cylinder. Due to the reciprocating motion of the piston, it is called reciprocating engine. 2 stroke and four stroke engines are the common examples of reciprocating engines.

4) Number of cylinders

Single cylinder engine: An engine which consists of single cylinder is called single cylinder engine. Generally, the single cylinder engines are used in motorcycles, scooter, etc.
Double cylinder Engine: The engine which consists of two cylinders is called double cylinder engine.
Multi cylinder Engine: An engine which consists of more than two cylinders is called multi cylinder engine. The multi-cylinder engine may have three, four, six, eight, twelve and sixteen cylinder.

5) Arrangement of Cylinder

Vertical engine
horizontal engine,
radial engine,
v-type,
w type,
opposed cylinder engine.

6) Valve Arrangement

L-head engine,
I-head engine,
F-head engine,
T-head engine.

7) Types of cooling

Air cooled engines.
Water cooled engines.

Q2. GIVE CLASSIFICATION OF AUTOMOBILE VEHICLES?

Ans: Automobile can be classified in several ways based on the following criteria :

I. Based on Purpose

Passenger vehicles : These vehicles carry passengers. E.g uses, cars, trains.
Special Purpose : These vehicles include Ambulance, Fire engines, Army vehicles.
Good vehicles : These vehicles carry good from one place to another place. Eg : goods lorry, goods carrier.

II. Based on load capacity

Light duty vehicle: small motor vehicles. E.g.: Car, jeep, Scooter, motorcycle.
Medium duty vehicle: relatively medium sized vehicles. e.g.: mini buses, small trucks.
Heavy duty vehicles: large and bulky motor vehicles. e.g.: Bus, Truck, Tractor

III. Based on fuel used

Petrol engine vehicles: Automobiles powered by petrol engine. e.: scooters, cars, motorcycles.
Diesel engine vehicles: Automobiles powered by diesel engines. e.: Trucks, Buses,Tactors.
Gas vehicles: Vehicles that use a turbine as a power source. e.g.: Turbine powered cars.Electric vehicles: Automobiles that use electricity as a power source. e.g.: electric cars,electric bus.

IV. Based on Number of Wheels

Two-wheeler: Mopeds, Motorcycles, scooters
Three – wheelers: Auto-rickshaws and tempos
Four-wheeler: Cars, Jeep, Bus, trucks
Six-wheelers: Buses and trucks have six tires out of which four are carried on the rear wheels for additional reaction. Eg: Tata T.12 Ultra Truck
Six axle wheelers: Tata Signa 4323.

V. Based on type of transmission

Manual transmission vehicles: Automobiles whose gear ratios have to be changed manually.
Semi-automatic transmission vehicles: Vehicles that facilitate manual gear change with clutch pedal.
Automatic transmission vehicles: Automobiles that are capable of changing gear ratios automatically as they move. e.g.: Automatic Transmission Cars.

VI. Based on side of drive

Left-Hand drive: Steering wheel fitted on the left-hand side.
Right-Hand drive: Steering wheel fitted on the right-hand side.
Fluid drive: Fluid Drive is the trademarked name that Chrysler Corporation assigned to a transmission driveline combination which replaced the flywheel with a hydraulic coupling and performed the same function as a modern torque converter, only without torque multiplication.

Q3. FOUR STROKE PETROL ENGINE?

Ans: Four stroke petrol engine is also knows as the spark ignition engine.

Its working cycle is consists of four strokes,These are suction, compression stroke, power stroke, exhaust stroke.
Four stroke petrol engine works on the otto cycle.

➢ Working cycle :

1) Suction Stroke:

While suction stroke, the piston moves from TDC to BDC with the intake valve is in open, condition and the exhaust valve in closed condition.
During this stroke, as the piston moves from TDC to BDC, a partial vacuum is created inside a cylinder that helps to suck (pull) the air fuel mixture from the intake manifold into the cylinder.
At the end of the suction stroke when the piston reaches the BDC, the inlet valve becomes closed.

2) Compression Stroke:

During the compression stroke, the piston compresses the air-fuel mixture to high pressure inside the cylinder.
For this purpose, the piston moves from the BDC towards TDC. During a compression stroke, both valves (Inlet and Exhaust) remain in a closed condition.
At the end of the compression stroke, the spark plug produces the spark to ignite the air-fuel mixture.

3) Power Stroke:

It is a stroke, in which power is obtained from the engine by the expansion of combustion products.
It is also called an Expansion Stroke because due to the burning of fuel, High-pressure gases expand inside the cylinder and force the piston downwards.
During power stroke the piston moves from the TDC towards BDC. At the end of the power stroke, the exhaust port opens.

4) Exhaust Stroke:

In Exhaust stroke, the piston moves from BDC to TDC.
During this stroke, burn gases are released to Exhaust Pipe through an exhaust port.
The exhaust valve closes when the exhaust stroke is completed.

Q4. TWO STROKE PETROL ENGINE?

ANS : In two-stroke engines, there are no suction and exhaust strokes. There are only two remaining strokes the compression stroke and power stroke. These are usually called upward

strokes and downward strokes. Also, instead of valves, there are inlet and exhaust ports in two-stroke engines

Diagram

Working of two Stroke petrol engine

The two-stroke engine cycle primarily is two halves, upstroke, and downstroke.
In the upward stroke the piston is the pushed from bottom dead center to the top dead center. This allows the fuel-air mixture to be compressed and the spark plug ignites the mixture.
This mixture then expands thus pushing the piston down. This opens the inlet valve lettering the mixture get sucked0 inside the crankcase.
When the mixture is pushed up into the combustion chamber during the previous upstroke, a partial vacuum is created.
This mixture gases into the combustion chamber during the down ward stroke.
During the down ward stroke the piston moves from top to bottom dead cell.
Thus allows the fresh air to enter the combustion chamber and mix with the fuel.
It is observed that in this stroke the crankshaft makes a rotation of 180 degree.

Q-5. FOUR STROKE DIESEL ENGINE?
Ans:

Four stroke diesel engine is also known as the compressed ignition (CI) engine since in this kind of engine the combustion occurs due to the compressing a air more than fuel self-igniti sion, both valves (Inlet & Exhaust) are closed.
Due to expansion stroke, power is obtained from the engine. Hence expansion stroke is also called a Power Stroke.
After the expansion stroke, the piston moves from BDC to TDC.
During this movement of the piston (BDC to TDC), the Burnt exhaust gases from the exhaust valve of cylinder are released through the engine exhaust pipe in the environment.
During this exhaust stroke, only the exhaust valve is open and at the end of this stroke, the exhaust valve closes and the inlet valve opens to suck (pull) fresh air.
Hence In this way the cycle continues and power obtains from the engine. on temperature.
The compression ratio of this engine is higher as compared to SI engine and it does not use the spark plug.
This engine works on the thermodynamic diesel cycle.
In this type of engine, the diesel is used as the fuel.
The four strokes in this engine are suction, compression, power as well as exhaust. The four processes in the Diesel engine are as follows:
- Process 1-2: Isentropic compression
- Process 2-3: Constant pressure heat addition
- Process 3-4: Isentropic expansion
- Process 4-1: Constant volume heat rejection
At the start, when the piston moves from TDC to BDC, from intake manifold air enters into the cylinder through the inlet port.
During this suction stroke, the inlet valve is open and at the end of the suction stroke the inlet valve closes.
After the suction stroke is done, the piston starts to move from BDC to TDC.
During this movement, the piston compresses the air to high pressure inside the cylinder.
During Compression, both valves (Inlet & Exhaust) are closed.
After the compression of air, the fuel injector sprays the fuel inside the cylinder, hence fuel gets ignited (catches fire).
Therefore Combustion starts, high-pressure gases expand (spread) inside the cylinder and push the piston downwards (towards BDC).
During this exhaust stroke, only the exhaust valve is open and at the end of this stroke, the exhaust valve closes and the inlet valve opens to suck (pull) fresh air.
Hence In this way the cycle continues and power obtains from the engine.

Q6. TWO STROKE DIESEL ENGINE?

ANS :

1st Stroke – As the piston starts rising from its B.D.C. position, it closes the transfer and the exhaust port. The air which is already there in the cylinder is compressed. At the same time with the upward movement of the piston, vacuum is created in the crank case. As soon as the inlet port is uncovered the fresh air is sucked in the crank case. The charging is continued until the crank case and the space in the cylinder beneath the piston in filled with the air.

2nd Stroke – Slightly before the completion of the compression stroke a very fine spray of diesel is injected into the compressed air (which is at a very high temperature). The fuel ignites spontaneously. Pressure is exerted on the crown of the piston due to the combustion of the air and the piston is pushed in the downward direction producing some useful power. The downward movement of the piston will first close the inlet port and then it will compress the air already sucked in the crank case. Just at the end of power stroke, the piston uncovers the exhaust port and the transfer port simultaneously. The expanded gases start escaping through the exhaust port and at the same time the fresh air which is already compressed in the crank case, rushes into the cylinder through the transfer port and thus the cycle is repeated again.

Q7. WRITE THE NOTE ON TRANSMISSION SYSTEM OF VEHICLES?

ANS : Transmission system is the system by means of which power developed by the engine is transmitted to road wheels to propel the vehicle. In automobiles, the power is developed by the engine which is used to turn wheels. Therefore, the engine is to be connected to the transmission systems for transmitting power to wheels. The engines employed in automobiles are of very high speed. Hence, a speed reduction is necessary to reduce the speed to moderate level as well as to get the required high torque while moving from rest. The power is transmitted to the differential unit through another universal joint.

Q8. Write the NOTE ON Transmission SYSTEM OF THE POWER AND MOTION WITH THE HELP OF SHAFT AND AXEL?

ANS : Power transmission is a process to transmit motion from one shaft to another by using some connection between them like belt, rope, chain, and gears. To connect the shafts, mainly two types of connectors are used, one is flexible and other is rigid. The transmission system, therefore, should fulfill the following requirements Enable the engine to keep disconnected from the road wheels. These should be connected only ‘when desired.’ Enable the engine, when running, to be connected smoothly and gradually without jerk to the road wheels.

Enable the leverage between the engine and the road wheels. Enable the reduction in the engine speed. Turn the drive through 90 degrees. It should enable the running of inner and outer road wheels at different speeds when the vehicle moves on a curved path. It should provide the relative motion between the engine and the road wheels when they move up and down due to the uneven road surface.

Propeller shaft: DIAGRAM
The third component of the automobile transmission system, which transfers motion from the gearbox end to the differential end. The distance between the two can be large, and therefore, it is a shaft which is thin and long to connect the two
Live axle:
The axle where motion from the crankshaft of the engine is transferred is known as a live axle. The other axle takes up only the load of the vehicle and therefore is termed as dead axle or simply the axle. The motion is generally transferred to the rear axle, but it can be transferred to the front axle
or both the axles. When the motion is transferred to both the axles, it is known as four-wheel drive. Finally, motion is transferred to the road wheels at the two ends of the live axle.

Q9. WRITE THE NOTE ON TRANSMISSION OF MOTION AND POWER WITH THE HELP OF BELT DRIVE?

ANS. Belt Drives are a type of frictional drives used for transmitting powers from one shaft to another by means of pulleys which rotate at the same speed or at the different speed. The portion of the belt which is having less tension is called slack side and the one which has higher tension is called tight side. The effective pulling power of the belt that causes the rotation of the driven pulley is the difference in tension on the slack and tight side. The tensions in the tight and slack sides of the belt depend on the angle of contact, the belt drives have to be arranged such that the slack side comes above and the tight side comes below the pulleys.

The following are the 5 main types of Belt Drives:

Open belt drive.
Cross belt drive.
Stepped cone pulley or speed cone drive.
Fast and loose pulleys.
Jockey pulley drive.

Q10. WRITE NOTE ON TRANMISSION OF MOTION AND POWER WITH THE HELP OF CHAIN DRIVE?

ANS: The chains are mostly used to transmit motion and power from one shaft to another, when the Centre distance between their shafts is short such as in bicycles, motor cycles, agricultural machinery, conveyors, rolling mills, road rollers etc. The chains may also be used for long center distance of up to 8 meters. The chains are used for velocities up to 25 m / s and for power up to 110 kW. In some cases, higher power transmission is also possible. Types of chains Roller chain: Roller chain is commonly used in bicycles, motor cycles, machine tools etc.
Silent chain: silent chain is inverted tooth chain which is used for smooth and noiseless operations at low speeds.
Advantages:

It is non-slip drive (positive).
Efficiency is very high (upto 99%).
It can be used form shafts which are at small and medium center distances.
It can transmit higher power than belt drives.

Q11. WRITE NOTE ON TRANMISSION OF MOTION AND POWER WITH THE HELP OF FRICTION DRIVE.

ANS:

Friction drive is used for light load transmission between parallel shafts or intersecting shafts.
Frictional shafts consist of two wheels their friction surface.
The driving and driven wheel are in contact with sufficient pressure between them. The driving wheel drives the driven wheel by virtue of friction between them. The friction wheel does not give a positive drive and slip occur for a large power transmission.
If there is no slip, the surface speed of both wheels will be equal. Four Types of Friction

Static Friction: Static friction acts on objects when they are resting on a surface.
Sliding Friction: Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction.
Rolling Friction: Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction.
Fluid Friction: Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases.

Q12. WRITE NOTE ON TRANMISSION OF MOTION AND POWER WITH THE HELP OF GEAR DRIVE.

ANS: Gear drive is used, when center to center distance between driver and driven shafts is very small. Gear is defined as “toothed wheels, which can transmit power and motion from one shaft to another shaft by means of successive engagement of teeth”.

It is important to note that, both the gears which are engaged, always rotate in opposite direction. Gear drive consists of two wheels. The smaller wheel is called pinion and the larger wheel is called as gear.
In gear, the slip is absent. Therefore, it gives exact and uniform velocity ratio. Due to this ability of maximum power transmission and exact velocity ratio, gear is called perfect positive drive.
Gears are generally used for one of four different reasons:

To increase or decrease the speed of rotation
To change the amount of force or torque.
To move rotational motion to a different axis (i.e., parallel, right angles, rotating, linear etc.)

Q13. WRITE A NOTE ON DESCRIBING AIR CONDITION OF VEHILCLE.

ANS: The air-conditioning system in a car works by manipulating refrigerant between a liquid and a gaseous state. As the refrigerant changes states, it absorbs heat and humidity from the vehicle and allows the system to give off cool, dry air. To change the refrigerant between a liquid and a gaseous state, the air-conditioning system works to control pressure and temperature. Automotive air-conditioning systems have a few key components.
Listed below are the main parts and their roles Compressor

Power unit of the system that separates the low-pressure side from the high-pressure side.
Takes in low-pressure gas and compresses it into high temperature/high-pressure gas.
Mounted to front of engine and driven by serpentine belt . Condenser
Reduces temperature of refrigerant while it maintains high pressure.
Refrigerant changes from gaseous state to liquid state as it cools.
Similar to the engine radiator, it uses forced air (fan or vehicle movement) to transfer he Mounted in front of vehicle, behind grill. Dryer
Removes water from the refrigerant using a desiccant (drying agent) Has some system-filtering properties.
Mounted on high-pressure side of system, between condenser and metering device. Metering Device
Either expansion valve or fixed orifice tube.
Lowers refrigerant pressure, which quickly drops refrigerant temperature.
Refrigerant is still in liquid form after leaving metering device.
Mounted on high-pressure side of system, between dryer and firewall. Evaporator
Refrigerant changes back to gaseous state in the evaporator, causing a cooling effect
Cabin air is cooled and dried as it blows across the evaporator.
Only component mounted inside passenger compartment, behind dashboard.
Path and characteristics of refrigerant
Low-temperature/low-pressure refrigerant enters the compressor (gas).
High-temperature/high-pressure refrigerant leaves the compressor (gas).
Refrigerant cools and converts to liquid in the condenser
Still under high pressure.
Receiver/dryer removes water from refrigerant.
Expansion valve reduces refrigerant pressure.
Refrigerant converts back to gaseous state in the evaporator.
Absorbs heat; when air blows across evaporator, it is cool and dry.

Q14. SHORT NOTE ON AIR BAGS?

ANS: The airbag system is perhaps the most important part of your vehicle when it comes to safety components.

An airbag is a vehicle occupant-restraint system using a bag designed to inflate extremely quickly, then quickly deflate during a collision.
It consists of the airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor.
The purpose of the airbag is to provide a vehicle occupant with soft cushioning and restraint during a collision.
It can reduce injuries between the flailing occupant and the interior of the vehicle.
The airbag provides an energy-absorbing surface between the vehicle’s occupants and a steering wheel, instrument panel, body pillar, headliner, and windshield.
Modern vehicles may contain up to 10 airbag modules in various configurations, including: driver, passenger, side-curtain, seat-mounted, door-mounted, B and C-pillar mounted side-impact, knee bolster, inflatable seat belt, and pedestrian airbag modules.
During a crash, the vehicle’s crash sensors provide crucial information to the airbag electronic controller unit (ECU), including collision type, angle, and severity of impact.
Using this information, the airbag ECU’s crash algorithm determines if the crash event meets the criteria for deployment and triggers various firing circuits to deploy one or more airbag modules within the vehicle.
Working as a supplemental restraint system to the vehicle’s seat-belt systems, airbag module deployments are triggered through a pyrotechnic process that is designed to be used once.

Q15. ABS (ANTI-LOCK BRAKING SYSTEM)?

ANS: An anti-lock braking system (ABS) is a safety anti-skid braking system used on aircraft and on land vehicles, such as cars, motorcycle, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maintaining tractive contact with the road surface and allowing the driver to maintain more control over the vehicle.

It works on the principles of cadence braking and threshold braking.
Cadence braking and threshold braking are techniques in which the driver applies and releases the brakes before locking the wheels, or applying and releasing the brakes before locking.
This process of braking and releasing the wheels is pulsing to prevent locking and the vehicle from skidding.
Drivers practice this technique to have better control of the vehicle when braking quickly and to prevent the vehicle from skidding.
The ABS system automatically performs this cadence of braking to prevent the wheels from locking or the vehicle from skidding when braking.
Although ABS generally offers improved vehicle control and decreases stopping distances on dry and some slippery surfaces, on loose gravel or snow-covered surfaces ABS may significantly increase braking distance, while still improving steering control.
Since ABS was introduced in production vehicles, such systems have become increasingly sophisticated and effective.
Modern versions may not only prevent wheel lock under braking, but may also alter the front-to-rear brake bias.
This latter function, depending on its specific capabilities and implementation, is known variously as electronic brakeforce distribution, traction control system, emergency brake assist, or electronic stability control (ESC).
At this point, you can control the steering to prevent the car from hitting obstacles.
In this way, the ABS system prevents the vehicle from skidding and provides more control over the vehicle to prevent accidents.

Q16. EBD (ELECTRONIC BRAKE DISTRIBUTION)?

ANS: Electronic brakeforce distribution (EBD or EBFD) or electronic brakeforce limitation (EBL) is an automobile brake technology that automatically varies the amount of force applied to each of a vehicle’s wheels, based on road conditions, speed, loading, etc, thus providing intelligent control of both brake balance and overall brake force. Always coupled with anti-lock braking systems (ABS), EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control. Typically, the front end carries more weight and EBD distributes less braking pressure to the rear brakes so the rear brakes do not lock up and cause a skid. In some systems, EBD distributes more braking pressure at the rear brakes during initial brake application before the effects of weight transfer become apparent.

Q17. TCS (TRACTION CRONTOL SYSTEM).

ANS: A traction control system (TCS), also known as ASR (from GERMAN :
Antriebsschlupfregelung, lit. ‘drive slippage regulation’), is typically (but not necessarily) a secondary function of the electronic stability control (ESC) on production motor vehicles, designed to prevent loss of traction (i.e., wheelspin) of the driven road wheels. TCS is activated when throttle input and engine power and torque transfer are mismatched to the road surface conditions.
The intervention consists of one or more of the following:

Brake force applied to one or more wheels.
Reduction or suppression of spark sequence to one or more cylinders.
Reduction of fuel supply to one or more cylinders
Closing the throttle, if the vehicle is fitted with drive by wires throttle
In turbocharged vehicles, a boost control solenoid is actuated to reduce boost and therefore engine power. Typically, traction control systems share the electrohydraulic brake actuator (which does not use the conventional master cylinder and servo) and wheel speed sensor with ABS.

Q18. CRUISE CONTROL?

ANS: Cruise control (also known as speed control, cruise command, autocruise, or tempo mat) is a system that automatically controls the speed of a motor vehicle. The system is a servomechanism that takes over the throttle of the car to maintain a steady speed as set by the driver.
Some advantages of cruise control include:

It is useful for long drives (reducing driver fatigue, improving comfort by allowing
positioning changes more safely) across highway and sparsely populated roads.
Some drivers use it to avoid violating speed limits. A driver who otherwise tends to
unconsciously increase speed over the course of a highway journey may avoid speeding.
Increased fuel efficiency.
Some disadvantages of cruise control include:
hazardous weather conditions
speeding around curves that require slowing down
Rough or loose terrain that could negatively affect the cruise control controls
Encourages drivers to pay less attention to driving, increasing the risk of an accident

Q19. GIVE THE TYPE AND APPLICATION OF FERROUS METAL AND NON-FERROUS
METAL IN AUTOMOBILE.

ANS: Properties of Ferrous Metals
Ferrous metals are any metal that contains iron, such as stainless steel. They are known for their tensile strength, which makes them ideal for architectural and structural uses such as the tallest skyscrapers, as well as bridges, railways and more. Ferrous metals are also have magnetic properties, which is why you can use magnets to pin things to your refrigerator door, although their high carbon content means that many ferrous metals are prone to rusting. The exceptions to this are stainless steel, which doesn’t rust because of the chromium, and wrought iron which doesn’t rust due to the high pure iron content.
Examples and Uses of Ferrous Metals
Commonly used examples of ferrous metals include steel, stainless steel, carbon steel, cast iron and wrought iron:

Steel : A combination of iron and carbon, steel is renowned for its strength and machinability. It is widely used in construction, manufacturing and industrial metal fabrication.
Stainless Steel: Stainless steel is an alloy steel made with the addition of chromium to steel, which provides resistance against rust.
Carbon Steel: Carbon steel contains a high carbon content that is added to iron to create an exceptionally hard metal that is used for tools.
Cast Iron: Cast iron is a hard and wear resistant metal that is widely used for items including cookware, machine tools, engines, manhole covers and water pipes.
Wrought Iron: Unlike most other ferrous metals, wrought iron is able to resist corrosion and oxidation. It is typically used for fences, railings and gates.

Properties of Non-Ferrous Metals
Non-ferrous metals don’t contain iron. They are lighter and more malleable than ferrous metals, making them ideal for applications where strength is required but weight is a consideration, such as with the aerospace industry. Non-ferrous metals are not magnetic but do offer good resistance to corrosion and can conduct heat and electricity. They are used in for items including industrial piping, gutters, roofing and electrical applications.
Examples and Uses of Non-Ferrous Metals
Commonly-used non-ferrous metals include aluminum, lead, silver, brass, gold, zinc, copper and tin:

Aluminum: Lightweight and easy to machine, shape and weld, aluminum is used for a range of applications from food cans and cookware to aeroplane parts and cars.
Copper: A good conductor of heat and electricity, copper is highly ductile and malleable. It is widely used for electrical wiring as well as in appliances and vehicles.
Lead: With a low melting point and low tensile strength, lead is used in electrical power cables, batteries, pipes, fuels, paint and for soldering.
Tin: Soft and malleable with a low tensile strength, tin is used as a coating to prevent steel from corroding.
Silver: Silver is used for a range of applications, including jewellery, cutlery, electrical contacts and in mirrors.
Brass: Brass is used for fixtures and fittings including taps, hooks, and doorknobs, as well as being used for light fittings and screws, among other uses.
Gold: Used for jewellery, gold also has applications including within the medical industry, in computers and also electronics.
Zinc: A medium strength metal with a low melting point, zinc is used to galvanise iron and steel to prevent rusting.

Q20. EXPLAIN SINGLE PLATE CLUTCH. EXPLAIN ITS CONTRUCTION. DRAW ITS NEEDED SKETCH.

ANS: A single plate clutch has one clutch plate. This clutch works on the principle of friction. It is the most common type of clutch used in motor vehicles.
The clutch primarily consists of two members, one mounted on the driving shaft and the other on the drive shaft. These two shafts are parallel and concentric with each other; one shaft is fixed to its housing while the other is splined so that it can move axially. The driving torque can increase by increasing the effective radius of contact.
CONTRUCTION OF SINGLE PLATE CLUTCH:

SINGLE PLATE clutch consists of different parts for proper working. They are arranged in a systematic order.
Mainly it consists of a clutch plate with both side friction lining and some other parts which help in the proper functioning of a clutch like a flywheel, pressure plate, thrust bearing, hub, springs, and input mechanism for engagement and disengagement of the clutch.
The clutch plate attaches to the hub between the flywheel and the pressure plate, it moves axially on the drive shaft.
In a single plate clutch, the clutch plate should have both side friction lining because it mounts between the pressure plate and flywheel, friction is responsible for the torque transmission.
The pressure plate engages with the flywheel and springs. Pressure plate helps to push the clutch plate with the flywheel.
A lever attaches to thrust bearings with some mechanism on the driven shaft which transmits input and output motion from the clutch pedal.