1.How petrol engine is different than diesel engine?
Answer: Petrol engine: Petrol engine works on the principle of Intake (fuel + air), Compression, Power and Exhaust. It means the fuel, and air will enter the combustion chamber, piston come upwards and compress the fuel. The compressed fuel comes in contact with spark plug and produces a spark that push piston down
Diesel Engine: In diesel engine the phenomenon is slightly different, there is no sparkplug in diesel engine. In here only air enters in the burning chamber, when piston is pushed up by motor, it will compress the air in the chamber, making it hot. Now valve opens and inject diesel, because of compressed air, the diesel blasts and push the piston down
2. Explain clutch system works?
Answer: Clutch system is made up of two metal plates adjacent to the engine. When you press the clutch pedal down the plates come apart separating the engine from the drive wheels allowing the drivers to change the gear, and re-engage the plates again with the engine once the gear is changed
3. Explain what is the benefit of dual clutch transmission?
Answer: The dual clutch transmission allows gears to be pre-selected before they are changed, so one clutch selects the second gear while the second clutch selects the third gear. There are usually seen in race cars
4. Explain what do you mean by independent suspension?
Answer: Independent suspension is referred to the mounting of the wheel on a separate axle. So, that road shocks affect only the particular wheel.
5. Mention the injector pressure in heavy vehicle?
Answer: Injector pressure in heavy vehicle is about 220 kg/cm square.
6. What is actual power delivered by the engine known as?
a) Shaft power
b) Horse power
c) Brake power
d) None of the mentioned
Answer: c
Explanation: The power delivered by the engine is called brake power.
7. If ‘T’ is torque(in Nm) and ‘N’ is speed(in rpm) then the required expression for Brake power ‘B.P’ in kWs is
a) 2πNT/6000
b) 2πNT/60000
c) πNT/6000
d) πNT/60000
Answer: b
Explanation: The required expression is B.P = 2πNT/60000.
8. The torque available at the contact between road and driving wheel is called
a) Brake power
b) Friction power
c) Tractive effort
d) Engine torque
Answer: c
Explanation: The torque between road and wheel is called tractive effort.
9. Which of these is not a power loss which takes place between engine and driving wheel
a) Power loss due to friction of piston bearings and gears
b) Power loss from clutch to drive wheel due to friction of various parts
c) Transmission line loss
d) None of the mentioned
Answer: d
Explanation: All the above mentioned losses are encountered while transmission of power
10. The force that opposes the motion of a vehicle is
a) Rolling resistance
b) Gradient resistance
c) Wind or air resistance
d) All of the mentioned
Answer: d
Explanation: Rolling resistance, gradient resistance and air resistance all oppose the motion of a vehicle.