Electrical Paper Test 2

1. What is the colour of a 10A fuse?  Red.
2. What is the total resistance in the circuit? 12A
3. The fuse is missing from a circuit. How do you measure & workout the correct fuse to replace? Check the fuse box cover. V=IxR  I= V/R. Measure before the fuse box and check with the components Amp rating.
4. What is the total resistance? 7A
5. Customer comes in with the passenger window N/W, What is the correct procedure to take? Measure the voltage at the connection. If good V then put a battery straight to the motor, if it works there must be a bad connection. If no Voltage at the connection, trace back to the switch. If good V at switch check the resistance for voltage drop. 
6. What colour is a 20A fuse? Yellow. 
7. Is the brake light bulb series or parallel? Parallel.
8. How does the central locking work on the front left door? When you lock or unlock the driver door, an electric motor lock or unlocks the passenger door. In the older cars they used vacuum hoses to lock and unlock. When you lock the door the vacuum sucks the lock shut when you unlock the vacuum pushes the lock open.
9.         What does this symbol mean and where would it be found in the car?  Stops the flow of electricity flowing backwards through the circuit and converts AC into DC in the alternator.
10. If a fuse doesnt work, how do you check it out? Get a test light and clip the alligator clip onto an Earth point. Apply power to the fuses, probe the pointy end into the fuses. One side should light up the test light but the other side should remain dead.
11. What is vvvvvvv and where would you find this on a car? Alternator. This is where the rectifier pack converts the AC into DC.
    
12. What Watts is a headlight bulb? This can vary but generally 50W on dip and 70W on high beam.
13. Explain how a relay works including both circuits? A relay is like a switch. When the relay receives low current input it opens or closes a switch which then allows high current to flow through the relay and power up a component. 
14. what is missing? V/   =R    IxR=              V/I=R    IxR=V
15. What is Voltage? Voltage is the strength of electricity flowing through a circuit.
    What is Amps? Amps is the amount of electricity flowing through the circuit.
    What is Resistance? Resistance is the force opposing the flow of electricity.

Electrical paper test

1) What is the correct PPE to be worn when carrying a battery.
     Safety Boots, coveralls, gloves, safety goggles
2) When charging a battery what are the five things you should do.
   Battery off the ground, keep away from metal, use a trickle charger, stable platform as not to spill it
3) What is the correct procedure to removing a starter motor.
   Remove battery terminals, remove wires from the starter motor. remove the 2 bolts holding the SM to the flywheel.
4) Three components used to check a battery.
   Volt meter, Hydrometer, Load Tester.
5) What is a short circuit.
  A short circuit is when a source of high resistance finds a path to ground of low resistance causing a spark.
6) What is a parallel circuit.
   A parallel circuit is when a source of power splits into two or more paths before joining back together.
7) When the car is running at idle, what voltage should be read on the alternator.
   14.5V
8) If the battery warning light is not working, what does this mean for the alternator.
   The light is complete on the alternator. this is to give it a little start to charge and keep it going.
9) What is the purpose of a relay.
   A relay is like a switch which receives a low current signal and open the pathway for a high current source to be complete.
10) What is Volts and Amps.
   Volts is the strength of the electrical charge and Amps is the amount of charge going through the circuit.
11) When using a multimeter, how should you connect in volts and amps.
   Volts should be connected in parallel with the components or wires, Amps should be in series with components.
12) When checking a battery, what are the SOP.
   accidentally shorting the battery. Keep the terminals clear, use the voltmeter and use each prong on the terminal.
13) What is the difference between the Alternator belts.
   V belt and Poly-V belt.
14) First two stages of a Starter Motor.
   When you turn the key the bendix engages pulling the lever, pushing the wheel out onto the flywheel. the second stage then engages and spins the wheel which turns the flywheel turning the motor over.
15) What is an Alternator and what is a starter motor.
   An Alternator charges the battery and a starter motor only starts the battery then its job is done.
16) What is the difference between the two.
   The alternator contains copper inside with magnets spinning on the inside using the belt. This creates a magnetic field, this charges the battery. The starter just spins the flywheel.
17) What is the acid inside the battery.
   Sulfuric acid
18) What is the 3 main numbers in the electrical module.
   30 positive 31 ground 15 ignition
19) What is voltage drop and how is it tested.
   voltage drop is when there is a significant drop in voltage across a wire or component. Use a voltmeter to check between battery 12.6V to the component which might be 6V
20) What component in the ALT converts AC to DC.
   The rectifier pack

TTEC3201 Electrical Technology

Industry Practice

Copy of TTEC 3206 Vehicle Technology

Engine diagram

Coolant Systems Q&A

Tuesday, August 13, 2013

Coolant system questions

1. What is the purpose of the water pump? Pumps the coolant through the engine using pressure.
2. How much energy is converted in to mechanical energy? 25%
3. What are the three ways of heat transfer? Convection, conduction, radiation.
4. What is the purpose of coolant? Anti freeze lowers freezing temp. raises boiling temp. lubricates the hoses and water jackets.
5. What are the main components of a cooling system. Radiator, Hoses, water pump, thermostat, heater
6. Why do we need flexible water hoses on the cooling system? As the engine runs it shakes, vibrates and moves around and firm solid pipes will stop the movement.
7. Why are coolant hoses reenforced?as the pressure builds the hoses start to bulge
8. How is the water pump driven? by pulleys on the pump and crankshaft drivn by a belt.
9. What is the water jacket? holes that are blasted into it and these form passage ways for the water to flow through and cool the engine.
10. What is the purpose of the thermostat? One way valve that when hot opens up and allows water to flow from the head to the radiator.
11. What is the purpose of the cooling fan? when idle-ing the fan turns on to pull cold air through the radiator.
12. Why do some cars have two cooling fans? Air Conditioning
13. On electric cooling fans, what switches the fans on and off? a temp sensor in the heads water jacket that switches on whe it reaches 90 degrees.
14. How does the temperature gauge work? the temp sensor in the head water jackets that works on resistance. When cold it has a lot of resistance and as it warms up there is less resistance as the particles expand and move apart.
15. Why do we have a radiator pressure cap? this keeps pressure in the cooling system, pressure raises the boiling point. When there is too much pressure it relieves the pressure from extra water into the overflow bottle and when there is not enough pressure a vacuum is created which sucks water back into radiator.
16. Why do we have a recovery bottle? store extra coolant and catches the overflow and lets water back into the system.
17. What is electrolysis? sparking of electricity using DC current to drive a chemical reaction, used for separating ores.