AUTOMOBILE ENGINEERING

UNIT I: VEHICLE STRUCTURES AND ENGINES

1. What are the functions of the frame? The functions of the frame are,

(a) To carry the weight of the vehicle and passengers(b) To withstand the engine and transmission torque(c) To bear thrust acceleration and breaking torque(d) To resist the centrifugal forces when cornering (e) To withstand bending and twist

2. What are the types of frame?The types of frame are,

(a) Conventional frame(b) Semi-integral frame(c) Integral or unitized (frameless) frame

3. What is integral (unitized/ frameless) frame?The body structure is fabricated to carry out the function of the body and frame. The units that are attached to the body are also riveted directly to the frame

4. What are the advantages of integral frame?The advantages of integral frame are,

(a) To reduce the weight (b) Less manufacturing cost(c) To absorb shock during accident

5. What are the forces acting on the frame and body?The forces acting on the frame and body are,(a) Heavy and suddenly applied loads for short duration(b) Inertia loads due to breaking (c) Impact loads during hitting (d) Overloading of the vehicle

6. What basis automobiles are classified?Automobiles are classified based on the following (a) Number of wheels and number of axles(b) Type of power plants (prime movers) used(c) Weight and load carrying capacity (d) Purpose served(e) Type of fuel used(f) Wheel drive system(g) Capacity of the engine

7. What are the classifications of IC engines according to speed?The classifications of IC engines according to speed are,(a) Low speed engine(b) High speed engine(c) Medium speed engine

8. What are the types of liner?The types of liner are, (a) Wet liner(b) Dry liner

9. What are the functions of the piston rings? The functions of the piston rings are,

(a) Prevention of lubricating oil film(b) Prevention of leakage of gas into the crankcase(c) Prevention of the lubricant entry into the combustion chamber (d) Prevention of carbon deposits and other impurities on the piston head

10. What are the types of oil control rings?The types of oil control rings are,

(a) One piece slotted cast iron type(b) One piece pressed steel type(c) Three piece steel rail type with expander

11. What are the types of balancing?The types of balancing are,

(a) Power balance(b) Mechanical balance

12. What is the firing order?The sequence in which the power impulses occur in an engineFiring order of 4 cylinder engine in 1-3-4-2Firing order of 6 cylinder engine in 1-5-3-6-2-4

13. What are the two types of valve mechanism used in four stroke engine?(a) Side valve mechanism (b) Over head mechanism

14. What do you understand by single cylinder engine and multi cylinder engine?Single cylinder engine consists of a cylinder suitable for less power production. Multi cylinder engine consist of more than one cylinder suitable for high power production

15. State the advantages of gas turbineThe advantages of gas turbine are

(a) Gas turbines are smooth in operation and suitable to continuous performance(b) There is no reciprocating part, hence it is easy to balance (c) It is free from vibrations (d) Suitable for high power production

16. What do you know about L-head engine?Inlet (Intake) and outlet exhaust valves are located at a side and operated by a single camshaft

17. What do you understand about T-head engine?Inlet (Intake) valve is located on one side and exhaust valve on the other side of the cylinder

18. What are the merits of Wankel rotary engine?(a) Wankel rotary engine is smaller in size(b) Lighter in size(c) More compact as compared to reciprocating engine

19. What is the main disadvantage of Wankel rotary engine?Higher oil conception per BHP is the main disadvantage of Wankel rotary engine

20. What is an engine displacement?Engine displacement is the total volume displaced by all the pistons of multi cylinder engine, as they move from TDC to BDC position

21. How are burnt gases scavenged in two strokes and four stroke engines?In 2-storke engines, air is blown into the cylinder through ports at the end of the power stroke and the exhaust valve or ports. Scavenging pump or blower provides the scavenging air

22. Name the three systems of airflow scavenging system in common use of 2-stroke engineThe three systems of airflow scavenging system in common use of 2-stroke engine are,(a) Cross scavenging (b) Loop scavenging (c) Unit flow scavenging

23. What is filler cap vent?A filler cap vent is small holes in the filler cap, which permit air enters and displaces the fuel

24. What is a drain plug?A drain plug fitted at the bottom of the fuel tank for emptying the fuel completely

25. What are the reasons for noisy in fuel pump operation?Low fuel supply and air leakage on the suction of the pump are the reasons for noisy in fuel pump operation

26. What are the methods of cooling in an IC engine?The methods of cooling in an IC engine are,(a) Air cooling (b) Water cooling(c) Evaporation cooling

27. What are the advantages of the water-cooling system?(a) Quick transfer of heat (b) Less engine sound(c) Easier method to control temperature

28. State the disadvantages of water-cooling system(a) Increase in weight of the vehicle (b) Corrosion of metal part(c) Freezing difficulties in cold weather

29. What is the distinct advantage of the air-cooled engine?Rapid warm up is the distinct feature in an air-cooled engine. The rapid warm up is useful in avoiding sludge and crankcase dilution

30. When should the radiator not be drained?The radiator should not be drained when it is fitted with anti-freeze device

31. What are wet and dry liners?Wet liner is one, which has outer surface direct contact with cooling water. Dry liner is a lining in which conduction of heat takes place through the cylinder walls through the water in the water jacket

32. What is water jacket? A water jacket is the space around the cylinder along which the cooling water circulates

33. What is bearing?Bearing is a device to support the rotating shaft with minimizing friction

34. Give a classification of bearings(a) Radial or journal bearing(b) Pivot or footstep bearing (c) Thrust or collar bearing

35. What is thermostat?A thermostat is check valves which opens and close with respect to the temperature of the cooling water in the radiator

36. What is supercharging (pressure charging)? Supercharging is a process of introducing air into the engine cylinder at a pressure higher than atmospheric pressure, thereby increasing the quantity of air consumed

37. How does supercharging increase the power of the engine?By increasing the amount of air, which provides more oxygen for combustion of a larger charge of fuel, the power of the engine increases

38. What is the purpose of supercharging?The purpose of supercharging is to increase the power may be required at intervals and give more power where space does not permit larger engines

39. Name the types of air cleaners used in an engines(a) Dry- fabric element air cleaners(b) Oil wetted wire woven element air cleaners(c) Oil bath element air cleaners

40. Which type of cleaner is more efficient?Paper element cleaner is more efficient

41. What is the basic difference between dry types, oil saturated type and oil bath air cleaner?

Dry air cleaner Oil saturated air cleaner Oil bath air cleanerAir passes though specially treated paper

Air passes through an oil saturated filter element

Air passes through an oil bath filter element

42. What is meant by turbulence as applied to diesel engine operation?Turbulence means the disturbance or agitation of the fuel spray and the air within the combustion chamber or cylinder

43. What methods are used to provide air turbulence?Different designs of spray nozzles, piston heads and pre-combustion chambers, which tend to create more violent agitation, are used to provide air turbulence

44. How does turbulence aid combustion?By causing an effective through mixing of the hot compressed air with the injected fuel oil, thereby bringing about more complete combustion and uniform cylinder pressure

45. Why should not the engine be cranked with the air cleaner off?If the engine backfires with the air cleaner off, it would cause fire in the engine compartment

46. What is fuel filter?Fuel filter is a part of the fuel pump fitted to prevent dirt in fuel from entering the pump of carburetor

47. What is canister oil filter?Canister oil filter is that which uses a replaceable filter element inside a permanent metal canister. This has a reusable steel shell with a replaceable cartridge or element inside

48. What is air lock?Air trapped in the pipeline which prevents the flow of fuel is said to be air lock

49. What is meant by air pollution?Exhaust gases let out by automobiles cause problems to people and mater. The substances that produce harmful effect on human beings and the environment are known as pollutants

50. What are the pollutants emitted by an automobiles?Nitrogen oxides (NOx), soot, carbon monoxide (CO), hydrocarbons (CH), aldehydes, cancer producing substances and components of sulphur and lead are the pollutants emitted automobiles

UNIT II: ENGINE AUXILIARY SYSTEMS

1. What is carburetor? It is a device for atomizing and vaporizing the fuel and mixing it with the air in varying proportions to suit the changing conditions of SI engines

2. What are the advantages of petrol injection?(a) High power(b) Low specific fuel consumption (c) No need of induction heating(d) Free from icing trouble

3. What are the classifications of battery?(a) Lead acid battery (b) Alkaline battery

(1) Nickel iron type(2) Nickel cadmium type

(c) Zinc air battery 4. What are the chemicals used in battery?

(a) Sponge leads (Solid)(b) Lead oxide (Paste)(c) Sulfuric acid (Liquid)

5. What are the types of drive arrangements?(a) Inertia drive

(1) Bendix drive(2) Folo-Tru drive

(b) Over running clutch6. Differentiate the battery ignition system and magneto ignition system

SI. No

Battery ignition system Magneto ignition system

1 Current is obtained from the battery Current is generated by magnet2 Easy starting Difficult starting 3 Less cost High cost 4 Used in Cars, buses, trucks Used in motor cycle, scooters, racing cars

7. What is spark plug?It is a device to produce electric spark to ignite the compressed air fuel mixture inside the cylinder

8. What is contact breaker?Mechanism to make and break the primary circuit of the ignition system for obtaining high voltage current in the secondary circuit is called contact breaker

9. What are the carburetor systems?Float, idling and low speed system, high speed system, accelerating pump and choke system are the carburetor systems

10. What is antiperculator? It is a device to relieve the vapour pressure in carburetor when hot weather

11. Why is gravity feed system not suitable for car and other heavy vehicles? Gravity feeding is not suitable for light motor vehicle like car and other heavy vehicles like bus as it is difficult to place the fuel tank at a level higher than that of the engine

12. What are the types of carburetors according to draft?(a) Horizontal draft(b) Updraft (c) Downdraft

13. What are the methods of fuel injection?(a) Air injection (b) Mechanical injection(c) Solid fuel injection

14. What is bleeding?Bleeding is the removal of air from the pipeline in injection system

15. What do you know about fuel spray nozzle?In the diesel engine, nozzle or device used for atomizing or cracking fuel oil and through which the fuel oil is injected into the working cylinder

16. What type of battery is used regularly in automobiles?Lead acid battery is used regularly in automobiles

17. What are the main circuits used in automobile electrical systems?(a) Starting circuit(b) Generator circuit(c) Ignition circuit (d) Lighting circuit

18. What is need (purpose) of cut-out relay in the automobile?Cut-out is a switch which connects or disconnects the battery from the dynamo automatically

19. What is the function of car’s generator?Generator is an electrical device which converts mechanical energy into electrical energy. When the generator is sufficiently turned by the engine, it furnishes electrical energy for all vehicles’ circuits, and replenishes the battery to keep it fully charged

20. Why solenoid is used in a starting circuit? Solenoid is used in a starting circuit for following purposes(a) To connect the magnetic winding with the battery (It will act as switch to reduce the length

of wire)

(b) To shift the pinions into the engagements with flywheel ring gear 21. Name the materials used to make the plate materials for separators in storage battery

(a) Chemically treated wood porous rubber(b) Resin- impregnated fiber

22. How are the positive and negative plates identified in the battery?The groups of the plate connected to the positive terminals of the cell consists of grids filled with lead peroxide and are identified by their brown color. The plate with negative terminals consists of grids filled with metallic lead and spongy nature and are identified by their dull gray color

23. What are the advantages of petrol injection system?(a) Specific fuel consumption is reduced (b) Volumetric efficiency is increased and hence increases in power and torque(c) Ease starting and acceleration and better performance (d) Blowback and icing can be eliminated (e) Suitable for racing cars and large engines

24. What are the classifications of an ignition system?(a) Battery ignition system(b) Magneto ignition system

25. What is pre-ignition? Pre-ignition system refers to the ignition of the combustible mixture before the spark occurring

26. State the causes of pre-ignition (a) Hot spots that occurs in the cylinder due to poor fitting of piston rings(b) Hot valves (c) Incorrect-insulation of spark plug

27. What are the methods used for starting diesel engines?(a) Hand cranking (b) Starting by cartridge (c) Electric starter motor (d) Hand-cranked inertia starter (e) Compressed air starting

28. What is the function of starting motor?Starting motor is rotated at a certain minimum sped in order for the engine to commence running by the fuel supply

29. Compare the contact breaker ignition and electronic ignition system

SI. No

Contact breaker ignition Electronic ignition

1 Contact points are made to get separated to make and break the circuit

An electronic control does the operation of making and breaking of the electric circuit

2 Primary circuit is opened by the breaker point

The primary circuit is opened and closed by ECU

3 Voltage is stepped up to 25000-30000 volts It produces up to 45000 V4 Wiring between the ignition coil and the

distributor is suitable for low voltage Wiring is made attached with proper insulation to handle high voltage

5 Spark timing system is mechanical or vacuum

The spark timing system is electrically controlled

30. What are the types of fuel pump?(a) Mechanical type(b) Electrical type

31. What are the basic requirements of a carburetor?(a) Reliable, durable and simple in maintenance and repair (b) Smooth operation at varying load(c) Good acceleration(d) Must be able to give full immediately after starting (e) Sufficient at high speeds(f) Good fuel economy(g) Even at low temperature, ease of starting(h) Steady operation at low idling speeds

32. What is the use of throttle valve in the carburetor?The throttle valve is operated by an accelerator pedal used to regulate the flow of air and fuel (petrol) mixture in the petrol engine to control the speed of engine

33. What is choke? When it is used?The choke is a butterfly valve in a carburetor, which is used to close the flow of air filter to carburetor in the petrol engine to produce rich mixture when starting of the engine

34. Name the different circuits of solex carburetor(a) Starting circuit (b) Idle and low speed circuit (c) Normal running circuit(d) Acceleration circuit (e) Float circuit

35. What are the objectives of the fuel injection system?(a) Fuel injection system must deliver the exact quality of fuel at the correct time for a wide

range of loads and speeds(b) The metered quantity of fuel injected should be constant from cycle to cycle of operation

in each cylinder(c) Injection of fuel should be at the desired rate so as to control the combustion and pressure

rise(d) Atomization of the fuel should be to the required degree(e) Fuel distribution should be uniform throughout within the combustion chamber(f) Beginning and closing of injection should be sharp

36. What is mono/ single point fuel injection system (SPFI)? Electromagnetic fuel injector which injects appropriate quantity of fuel immediately into the intake manifold at a central point ahead of the throttle valve called central fuel injection (CFI)/ throttle body injection (TBI)/ Mono-jetronic (Bosch system)/ mono point fuel injection system/ single point fuel injection system (SPFI)

37. What is multi point fuel injection system (MPFI)? Injects the fuel on the induction stroke of each cylinder in the engine firing order is called MPFI

38. What are the three types of starting devices in use?(a) Bendix drive

(b) Over- running clutch drive (c) Solenoid drive

39. What are the three types of ignition system?(a) Battery ignition system(b) Magneto ignition system(c) Coil (Contact breaker) ignition (d) Electronic ignition

40. List out the basic requirements for ignition system(a) A source of electrical energy (b) Method to boost low voltage to very high voltage (c) High tension sparks for the ignition of the mixture(d) Method to distribute the high potential to individual spark plug at the proper instant

41. What are the three types of regulator? (a) Voltage regulator (b) Current regulator (c) Current-voltage regulator

42. What is voltage regulator?The voltage regulator controls the voltage of the circuit so as not to exceed a pre-determined value and to maintain constant voltage of the system

43. What is current regulator? The current regulator controls the maximum amperage of current output of the generator. This also prevents the generator from damage due to overload

44. What is the function of a carburetor?The function of a carburetor is to produce a mixture of petrol vapour and air in a correct proportion

45. What are the main elements of a carburetor?(a) A barrel which air horn(b) Float chamber

46. What is direct injection system?Direct injection system is one in which the fuel is injected directly into the float chamber of a petrol or diesel engine

47. What are the advantages of electronic fuel injection (Motronic) of SI engine?The advantages of electronic fuel injection (Motronic) of SI engine are, (a) Maximum fuel economy(b) Limits improved by exhaust emissions, preignition and drivability

48. What is the principle feature of common rail fuel injection system?The common rail’s (CRs) principle feature is that the fuel injection pressure is independent of the engine speed and the quantity of injected fuel

49. What is battery?The battery stores the electrical energy supplied by the alternator/ generator after converting the same into chemical energy

50. What are the components of lead acid battery? Container or case, positive and negative plates, separators, cell covers, electrolyte, straps and interconnections between cells are the components of lead acid battery

TRANSMISSION SYSTEMS: UNIT III

1. What are the requirements of clutch?(a) Gradual engagement (b) Torque transmission (c) Heat dissipation (d) Vibration damping (e) Dynamic balancing (f) Free pedal play (g) Ease of operation

2. What are the types of clutch?(a) Cone clutch (b) Single plate clutch (c) Multi plate clutch (d) Diaphragm clutch (e) Hydraulic clutch (f) Magnetic clutch

3. What are the types of transmission system?(a) Mechanical transmission (b) Hydraulic transmission(c) Electrical and electromagnetic transmission

4. What are the materials used for friction disc lining?Leather, cock, cotton fabric and asbestos based materials the materials used for friction disc lining

5. What are the types of gear box?(a) Sliding mesh (b) Constant mesh(c) Epicyclical

6. What is the use of universal joint?Universal joint takes care of the vibration in the inclination of the propeller shaft

7. What are the functions of the differential?(a) It splits the power that is received and sends the same through the two half axle shafts to

the driving wheels (b) It allows the two driving wheels to turn by the same amount, when the vehicle goes on a

straight path (c) It allows the driving wheel to turn by different amounts when the vehicle goes around a

curve and at the same time delivers power to both the wheels8. What are the functions of the transmission?

(a) To disconnect the engine from the driving wheels when starting the engine(b) To connect the driving wheels smoothly and without to the engine, when the engine

running (c) To vary the leverage between the engine and driving wheels (d) To turn the drive through 90 degree

9. What do you know about gear box?Gear box varies the leverage (speed ratio and hence torque ratio) between the engine and the driving wheels

10. What is fluid fly wheel (fluid coupling)?A liquid coupling is used to transmit engine turning effort (torque) to a clutch and transmission (Automatic clutch)

11. What are the needs of gear box in an automobile?Gear box is necessary to regulate both the power output and the speed range of the engine relative to the vehicle speeds

12. What are the different types of gear box used in an automobile?(a) Sliding mesh gear box(b) Constant mesh gear box(c) Synchromesh gear box(d) Planetary gear box

13. What is tractive effort?Tractive effort is the driving force that acts at the driving wheel to propel the vehicle. Tractive effort is proportional to the engine torque

14. What is the principle of synchromesh gear box?Basic principle of the synchromesh gear box is first to bring into frictional contact. That member which is ultimately to be engaged positively and then as friction and speed are equalized to make the positive contact

15. What is the function of a synchronizer in a gear box?The function of synchromesh in a gear box is to synchronize the speeds of the parts to be engaged, by friction before undergoing positive engagement. These synchronizers are used in contact mesh gear boxes for smooth engagement without clash and damage

16. What is overdrive? Overdrive is a device interposed between the transmission and propeller shaft permit the propeller shaft to run faster than on overdrive the transmission main shaft

17. What is the main advantage of liquid coupling?A liquid coupling, when used with a conventional clutch and transmission enables the driver to use the clutch and gears with less skill and fatigue than with a mechanical linkage

18. What is the necessity of the propeller shaft?A propeller shaft is provided to hope with and maintain the distance between the gear box and the differential, to adjust with the varied length and angle

19. What is meant by differential?Differential is the mechanism housed in the drive axle, which drives the outer wheel faster than inner one while taking a turn

20. What is referred as an axle?It is a steel shaft that support weight of the vehicle and transmit torque from the differential to the drive wheels

21. What are the types of rear axles used in vehicles?(a) Semi-floating (Fiat and jeep)(b) Three quarter floating axle (Ambassador)(c) Full floating axle (Trucks, buses)

22. What are the features of the good clutch?(a) Pick up load without any noise (b) Have capacity to damp out vibration(c) Need least pedal pressure to function

23. Why multiple clutches used in heavy vehicles? Multi clutches is used to transmit more power by providing more contact area in compact package

24. What is meant by a wet clutch?A wet clutch is one, which runs oil in which the plates are lined with cork

25. What is the function of stator in converter?The stator causes the torque converter to multiply the torque and temperature and due to whipping action of teeth, a special lubricant called as extreme pressure lubricant is used

26. State the functions of the front axle(a) Bears the front weight of the vehicle (b) Turns the front weight easily (c) Provides cushioning affect through the spring

27. What types of sections are provided at the middle and at the ends of the front axle?I-section is provided at the middle and elliptical section at the ends of the front axle

28. What is meant by wheelbase?Wheelbase refers to the distance between the front and rear wheel axle of the car, when in a straight head position

29. What is a universal joint?Joint, which permit power to be transmitted from one shaft to another, which are not in alignment is known as a universal joint

30. What are the various universal joints in use?(a) Cross type universal joint (b) Ball and trunnoin universal joint (c) Constant velocity type universal joint

31. What is the special feature of differential lubrication?Since the differential gear is operated at extreme high pressure and temperature and due to whipping action of teeth, a special lubricant called as extreme pressure lubricant is used

32. What is the major drawback of Hooke’s type universal joint?Suppose one of the shafts in Hooke’s joint is revolving at a constant speed, then the other shaft will not revolve at the same constant speed; but during two parts of the revolution, the shaft revolve at slightly lesser speed and for the other two parts at a slightly greater speed than the constant speed of the first shaft

33. What is the constant velocity type universal joint?A joint, which does not allow variation in angular velocity occurring in each revolution, is known as constant velocity universal joint

34. What is the advantage of the constant velocity universal joint?The advantage of the constant velocity universal joint is the elimination of transmitted speed fluctuations

35. Why are constant velocity joints necessary?To avoid fluctuations of speed or to get uniform motion, constant velocity joint is used

36. Explain the construction of universal jointThe construction of universal joint consists of a double-hinged joint with two Y-shaped yokes and a cross member known as spider

37. What is a spider?Spider is a cross-shaped member of a cross and yoke type universal joint

38. What is trunnion?The four arms of the spider, which connects two yokes of the universal joint, are called trunnions

39. How does the hail and trunnion universal joint differ from the cross type?Ball and trunnion permits shaft endplay, so that there is no need for the slip joint unlike in the cross type

40. What is known as ball and socket joint?A ball and socket joint is a flexible joint consisting of a ball within a socket, used in suspension systems and valve-train rocker arms

41. How many universal joints are there in the torque tube transmission and why?Only one universal joint is provided at the gear box end, as the torque tube is bolted to the axle casing and movement is confined to the front end

42. What is the function of the free wheel in overdrive?With the freewheeling device, power transmission from the shaft to the output shaft is possible when the sun gear id locked

43. What are the advantages of the single plate clutch?(a) Very simple in construction (b) Only a little effort is needed from the driver (c) Friction lining can be replaced separately (d) Clutch plate is durable

44. What are the advantages of diaphragm clutch?(a) Lesser operating pressure is required (b) Design is compact(c) No need of release levers(d) Accurate balancing is made available always and heavy vibration is avoided(e) Less affected by centrifugal force comparatively (f) It can withstand higher speed(g) Uniform and constant load on the driver plate

45. What are the merits of centrifugal clutch?(a) Automatic engaging and disengaging of pressure plate with respect to speed (b) Suitable for small vehicles (c) Clutch pedal and springs are eliminated(d) Driving is very easy and convenient

46. What are the advantages of flywheel?(a) The engine can idle without disengagement of gears (b) Fuel economy is obtained (c) Less wear on transmission (d) The unit can be put off action when required because positive clutch is possible

47. What are the advantages of overdrive?

(a) Engaging and disengaging is easy (b) Vibration and noise is reduced (c) Engine life is increased (d) Improved fuel economy (e) Increased gear ratio is available(f) Engine wear and loss of power reduces as the engine speed is lower

48. Compare the fluid coupling with torque converter

SI. No

Fluid coupling Torque converter

1 Contains impeller and turbine Contains impeller, turbine and a stator 2 Torque transmission unit Torque multiplication unit 3 Serves as an automatic clutch Serves as an automatic clutch as well as

torque multiplier 4 Efficient at high speeds Inefficient at high speeds but high efficient

under load

49. What is clutch?The clutch is the friction mechanism used to connect or disconnect the power depends on the requirements from the engine to gear box in an automobile transmission

50. What are the functions of clutch?(a) To engage or disengage the rest of the transmission as required (b) To transmit the engine power to the rear wheel without shock(c) To enable the gear to get engaged when the vehicle motion

UNIT IV: STEERING, BRAKES AND SUSPENSION

1. What are the functions of suspension system?(a) To absorb the shocks and vibrations (b) To carry the load

2. List out the types of stub axle (front axle)(a) Elliot (b) Reverse Elliot (c) Lemonine (d) Inverted lemonine

3. What are the qualities of the steering system? (a) It must keep the wheels at all times in rolling motion without scuffing (rubbing) on the road(b) According to the requirements, the system should assist in controlling the speed of the

vehicle(c) Steering must be light and stable with a certain degree of self adjusting ability(d) The steering system should also absorb road shock (e) It must be easily operated with less maintenance

4. What is shackle?Shackle is a mechanical device which is used to compensate for changes in its length of the leaf spring

5. What are the purposes of camber angle?

(a) To bring the road contact of the tyre more nearly at or under the point of the load(b) To provide easy steering by allowing the vehicle weight to be carried by the inner wheel

bearing and spindle 6. What are the requirements of an automobile wheel?

(a) To absorb road shocks (b) To carry load of the vehicle(c) To transmit propeller and brake force(d) Be sufficiently strong to withstand the weight of the vehicle (e) Be flexible to absorb road shocks (f) Be properly balanced statically and dynamically (g) Light as possible (h) Ease to remove and mount

7. What are the types of wheel?(a) Disc wheel (b) Spoked wheel(c) Mag wheel(d) Heavy vehicle wheel

8. What are the advantages of wheel alignment?(a) Good directional stability (b) Good riding comfort (c) Minimum tyre wear (d) Easiness in steering (e) Reversibility of steering gear

9. What are the needs of suspension system?(a) To safeguard the passengers and good against road shocks (b) To prevent the road shock from getting transmitted to the vehicle body (c) To preserve the stability of the vehicles while in motion (d) To maintain proper steering geometry

10. What is the use of differential unit?Enables the tow driving wheels to be driven equally. It also permits the two driving wheels to be turned at unequal speeds, when the vehicles moves over an arc

11. Why should not be brake drums are too close to the rim?Brake drums should not be closed, as the brake heat is conducted to the tyre, moreover if clearance is sufficient, ventilation is also restricted

12. What is steering ratio?A steering ratio is defined as the number of turns the steering wheel has to make for one turn of pitman arm

13. What is known as reversibility in the steering wheel?If the stub axle movement makes the steering wheel to turn, then the steering gear is said to be reversible

14. List out the factors that tend to increase brake temperature (a) Load on vehicle(b) Speed of vehicle (c) Maladjustment of brakes

(d) Unbalanced braking 15. Why does ‘high pedal’ produce better braking action than ‘low pedaling’?

High pedal is with higher leverage or mechanical advantage. Therefore, a small force is sufficient to apply at the pedal to produce relatively a large force against the brake shoes

16. Define reaction time as referred to brake applicationReaction time refers to the time needed to move the foot and apply the brake

17. What is the major advantage of a disc brake?The major advantage of a disc brake is its resistance to fading and its tendency to remain cooler even under repeated applications

18. What is camber?Camber is the inclination of the front wheel tyre with respect to the vertical line

19. What is caster?Caster is the slant of the steering axis as viewed from the side of the vehicle

20. Write the difference between camber angle and caster angle systems

SI. No

Camber angle Caster angle

1 Camber is the inclination of the front wheel tyre with respect to the vertical line

Caster is the inclination of the steering axis as viewed from the side of the vehicle

2 Used to bring the road contact of the tyre Used to obtain directional control of the vehicle

21. What is toe-in?The front distance of the wheels is less than the rear distance, the wheels are said to be toe-in

22. What is toe-out?The front distance of the wheels is greater than the rear distance, the wheels are said to be toe-out

23. Write the difference between toe-in and toe-out

SI. No

Toe-in Toe-out

1 The front distance of the wheels is less than the rear distance

The front distance of the wheels is greater than the rear distance

24. What are the types of tyre?(a) Tubed type tyre (b) Tubeless type tyre

Types of carcass tyre are,

(a) Cross ply (Bias ply)(b) Radial ply(c) Belted bias

25. What are the causes of under-inflation?(a) Uneven wear (b) Lack of directional stability (c) Excessive flexing of side rolls (d) Increase in rolling resistance

26. What are the causes of over-inflation?

(a) Less type grip(b) Impact resistance reduced (c) Contact area reduced between road and tyre(d) Uncomfortable because of vibration (e) Less rolling resistance

27. What is king pin inclination?King pin inclination is the angle between vertical line and axis of king pin when view from the front

28. What are the advantages of front independent suspension system?(a) Improved ride quality (b) Better road holding (c) Improved steering control (d) Reduced axle tramp (e) Less variations in caster angle (f) Reduced pitching (g) Better packaging

29. What are the types of steering gear box?(a) Worm and worm sector/ wheel steering(b) Screw and nut steering(c) Cam and roller steering(d) Rack and pinion steering (e) Recirculating ball steering

30. What is objective of power steering?Reduced the driver’s effort in steering is the objective of power steering

31. What do you know about power steering?External power (compressed air, electrical system or hydraulic pressure) is used to assist the manual steering operation called power steering

32. What are the advantages of power steering?(a) Reduced the driver’s effort (b) Suitable for heavy vehicles

33. What is wheel alignment?Wheel alignment is defined as refitting of suspension parts to an original specification, thereby ensuring design performance

34. What are the important factors affecting the steering geometry?Kin pin inclination, wheel alignment, suspension system, toe-in, toe-out, camber angle, caster angle are the important factors affecting the steering geometry

35. Why spoked wheel used for two wheelers?(a) Low weight (b) Less cost (c) High damping (Absorbs the road shocks)

36. What type of wheel is suitable for light motor vehicle?Disc wheel is suitable for light motor vehicle

37. What are the limitations of spoked wheel?(a) Should not carry heavy weight

(b) Less life (c) Complicated construction

38. What is tyre? The tyre is a flexible cover for the tube and provides production. It is placed around the rims of the wheels as a cushion between the wheel and the road

39. Differentiate the radial and plain tyres

SI. No

Radial tyre Plain tyre

1 Tyre pressure is less Tyre pressure is high2 Suitable for comfort Not suitable 3 High road grip Less road grip4 High cost Less cost

40. What are the advantages of tubeless type tyre?(a) There is no separate tube (b) Puncher is not possible (c) No need of powders to separate tube and tyre to avoid sticking

41. What are the disadvantages of tubeless type tyre?(a) High cost(b) Difficult to manufacturing

42. What are the advantages of tubed type tyre? (a) Less cost (b) Tube replacable

43. What are the functions of tyre?(a) To provide riding comfort of automobiles (b) Cushioning of vehicle against the road shocks (c) Transmission of driving and braking torque (d) To be responsible for stability of the vehicle and steering (e) To provide better mobility (f) Development of cornering and directional stability

44. What are the disadvantages of Tubed type tyre?(a) There is separate tube (b) Puncher is possible(c) Powder required to separate tube and tyre to avoid sticking

45. Write the difference between independent and common suspension systems

SI. No

Independent suspension system Common suspension system

1 Separate suspension for left and right wheels

Common

2 Suitable for small and light motor vehicles

Suitable for heavy vehicles

3 Suitable for small passenger cars Not suitable 46. Differentiate the tubed and tubeless type tyre?

SI. No

Tubed type tyre Tubeless type tyre

1 Separate tube is available There is no separate tube 2 Puncher is possible Not possible

47. Differentiate the leaf spring with coil spring

SI. No

Leaf spring Coil spring

1 Stiffness is depends on leafs used Stiffness is depends on coil2 Suitable for heavy vehicles Suitable for small and light motor vehicles 3 High stability Les stability4 More space is required Less space is required

48. What is tyre retreading or recapping? The worn out tyres can be replaced. If the fabric of tyres and the casing are not required, then the tyre can be repaired, by replacing the worn tread with a new one. This renewing process of tread is called as retreading or recapping

49. Write the difference between under-inflation and over-inflation of tyres

SI. No

Under-inflation of tyre Over-inflation of tyre

1 Increase in rolling resistance Less rolling resistance2 More tyre grip Less tyre grip 3 Contact area increased Contact area reduced between road and tyre 4 Comfortable Uncomfortable because of vibration

UNIT V: ALTERNATIVE ENERGY SOURCES

1. What are the types of fuel used in an IC engine?(a) Liquid (Diesel and petrol)(b) Gas (LPG, CNG and Hydrogen)

2. What is the use of an (anti-icing compounds) anti freezing compounds?Antifreezing compounds are used to eliminate the formation of ice of fuel (Petrol/ Diesel)

3. List out the Antifreezing compoundsEthanol, distilled glycerin, propylene glycol, mixture of alcohol and glycerin, denatured alcohol and ethylene glycol are the Antifreezing compounds

4. List out the few alternative fuels used in an automobileLPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), alcohols (ethanol and methanol) and hydrogen are the few alternative fuels used in an automobile

5. What is the use of an automobile?Antioxidant prevents the formation of gum while the gasoline is in storage tank

6. What are the advantages of LPG?(a) Extremely economical when large distances are covered (b) Emissions from an LPG engine are substantially lower than those achieved with gasoline

(petrol) or diesel

(c) Life of the engine is increased (d) Less maintenance cost

7. What do you know about fuel cells?The fuel cells are electrochemical cells in which chemical energy of a suitable fuel is continuously converted into electrical energy using atmospheric oxygen

8. What are the advantages of electric vehicle?(a) Less noise(b) No exhaust emissions

9. What do you know about hybrid vehicles?The term hybrid drive denotes such vehicle drives with more than one drive source. Hybrid drives can incorporate several similar or dissimilar types of energy stores and/or power converters

10. What are the advantages of hybrid vehicle?(a) More flexibility (b) High efficiency

11. What are the limitations of LPG?(a) Special safety precautions are necessary (b) Availability is less(c) Lower cruising ranges and increased fuel volumetric consumption compared to gasoline

(Petrol)(d) Pressurized gas cylinders require a lot of space

12. What are the components incorporate with typical LPG systems?(a) LPG tank, with ventilation line(b) External filter valve designed to interrupt refueling at 80% of container capacity (c) Flow interrupt valve(d) Pressure regulator for evaporator, with cooling (e) Venture mixing unit/ Gas injector nozzle(f) Electronic control unit (ECU)(g) Servomotor for controlling gas follows(h) Switch for altering between LPG and gasoline operation(i) Lambda oxygen sensor(j) Vacuum sensor/ Air intake pressure sensor

13. What are the salient features of CNG comparatively?(a) CNG is a safer fuel than petrol, diesel and LPG(b) CNG has 0.587 specific gravity, it is lighter than air(c) CNG has 7000C ignition temperature compared 4500C for petrol

14. What is the composition of CNG?Methane (CH4) about 80 to 90%, a smaller amount of ethane (C2H5), traces of other lighter hydrocarbons and small amounts of CO2 and N2

15. What are the advantages of CNG?(a) Life of the engine is increased (b) Less maintenance cost (c) Extremely economical when large distances are covered(d) Emissions from a CNG engine are substantially lower than those achieved with gasoline

(petrol) or diesel

16. What are the disadvantages of CNG?(a) High production cost (b) Special safety precautions are necessary (c) Availability is less(d) Pressurized gas cylinders require a lot of space

17. What are the advantages of hydrogen?(a) Hydrogen has high self ignition temperature (b) Hydrogen has very low density in gas and liquid stages (less than one tenth of air)(c) Hydrogen has to be stored as gas and liquid stages (d) Hydrogen has extremely wide ignition limits (e) Emissions from a hydrogen engine are substantially lower than those achieved with gasoline

(petrol) or diesel 18. Differentiate the LPG with CNG

SI. No

LPG CNG

1 Liquefied petroleum gas Compressed natural gas2 Mixture o flight hydrocarbons, propane

and butane Methane (CH4) about 80 to 90%, a smaller amount of ethane (C2H5), traces of other lighter hydrocarbons and small amounts of CO2 and N2

3 Pressure: 4-15 bar Pressure: 240-250 kg/sq.cm19. What are the salient features of alcohols?

Alcohols have higher anti-knock characteristics compared to gasoline. Compression ratio ranges between 11:1 to 13:1. Higher compression becomes possible. Alcohol contains about half the heat energy of gasoline per liter

20. What are the disadvantages of electric vehicle?(a) High speed and acceleration is not possible(b) Not suitable for high load and heavy vehicle (c) Large space needed to batteries to store the electrical energy

21. What are the essential requirements of the battery of electric vehicle?(a) High energy and power density (b) Excellent cycle life(c) Good reliability and high safety (d) Easily from the environmental view point and recyclable

22. What do you know about hybrid vehicle?The term hybrid denotes such vehicle drives than one drive source. Hybrid drives can incorporate several similar or dissimilar types of energy stores and/or power converters

23. What is known as smog in an automobile?Smog in automobile is a mixture of unburnt fuel and soot in air

24. What are the properties of petrol?Petrol is highly volatile, inflammable, colour; high heat value and anti-knock are the other properties of petrol

25. What is volatility?It is the property of the fuel, which states the case with which a liquid vaporizes

26. What are the effects of low volatility of gasoline?Low volatility of gasoline results in poor vaporization and condensation in intake manifold

27. What characteristic of the fuel affects easy starting?Volatility of gasoline affects easy starting

28. What is meant by unleaded gasoline?Unleaded gasoline refers to petrol to which no lead compounds have been intentionally added. Even gasoline which contains 0.05 g or less of lead per gallon may be referred to as unleaded gasoline

29. How does gum affect engine operation?Stuck valves and piston rings, excessive engine deposits, coated intake manifolds, clogged carburetor jet, etc., are the difficulties experienced by the presence of gum in gasoline

30. What is a vapour lock?A vapour lock is the condition in the fuel system when fuel vaporizes, causing the presence of bubbles in the gasoline vapour distributing fuel delivery to the carburetor

31. What is octane rating of fuel?It is the measure of fuel ability to resist ignition knock

32. Differentiate the LPG with petrol

SI. No

LPG Petrol

1 Liquefied petroleum gas Liquid fuel2 Stored in cylinders (Mixture of light

hydrocarbons, propane and butane)Stored in tank

3 Automatically supplied (Pressure: 4-15 bar)

Gravity feed or pump is used

33. What is tetra ethyl lead?Tetra ethyl lead is a common additive to gasoline to increase its knock resistance

34. What are the elements of a typical electric vehicle drive system?(a) Energy storage battery (b) Electronic power converter and associated controller (c) Drive motor (d) Transmission/ speed reducer

35. Indicate the different types of hybrid vehicles(a) Hybrid drive with mechanical energy store(b) Hybrid drive with electrical energy store (c) Hybrid drive with IC engine and electrical energy sources

36. What are the types of hybrid system (Hybrid drive train system)?(a) Series system(b) Parallel system(c) Series-Parallel system

37. What are the advantages of hybrid system?(a) Low emissions(b) Cost of engine is low comparatively (c) Lesser fuel consumption

38. What are the disadvantages of hybrid system?

(a) Suitable for short distance only (b) High cost and complicated construction

39. What are the (needs) reasons to develop fuel cells?(a) Depletion of conventional types of fuels leading to energy crisis(b) Low emissions required to make a car economic friendly(c) To attain certain standards of emissions control

40. How can octane rating be increased?Octane rating can be increased by the addition of anti-knock compound, like tetra ethyl lead

41. What are the main components of a hybrid car system?(a) An electric motor (b) A generator (c) An IC engine

42. What are the disadvantages of fuel cells?(a) Increased load capacity (b) An elaborate storage methods for hydrogen have to be used(c) Complicated and costly construction

43. Differentiate the electric vehicle with petrol/ diesel vehicle

SI. No

Electric vehicle Petrol/diesel vehicle

1 Electrical motor is the power source IC engine is the power source2 Electrical energy is stored in the battery Engine produces the energy by petrol/diesel 3 Less noise More noise4 Less power produced More power produced5 Less pollution More pollution

44. What are the needs for CNG?(a) To reduce urban pollution (b) To reduce global concern for environment (c) Reducing vehicle pollution (d) Economic

45. What are the advantages of alternative fuels?(a) Increased load capacity (b) Elaborate storage methods(c) Simple construction (d) Less pollution (e) Fuel cost reduced

46. What are the disadvantages of alternative fuels?(a) Separate storage required (b) An elaborate storage methods for hydrogen have to be used (c) Complicated and costly construction

47. What do you know about emissions?During combustion, pure hydrogen (H2) oxidizes to form water (H2O). NOCO2 is produced by the combustion process. H2 is thus the only fuel which can be used to avoid all CO2. Electric drive is the only alternative which can make a similar claim. Adiabatic flame temperature for hydrogen is

little lower than for gasoline, but rapid combustion allows very little heat loss to the surroundings and hence, high instantaneous local temperatures are produced. This leads to high nitric oxide formation

48. What are the disadvantages of hydrogen?(a) High production cost (b) Special safety precautions are necessary (c) Availability is less(d) Pressurized gas cylinders require a lot of space

49. What are the advantages of fuel cells?(a) Very low emission of pollutants (b) The oxygen air bags are very useful for the passengers (c) The cell prevents the depletion of the fossil fuel(d) The carbon dioxide exhaled by the passengers is also removed (e) Products are water, heat and electricity. There are no oxides of nitrogen, HC and CO(f) Provide all benefits of the battery and more along with extended range (g) High efficiency and low emissions

50. What are the needs for alternative fuels?(a) To reduce urban pollution (b) To reduce global concern for environment (c) Reducing vehicle pollution (d) Economic