Observation

      The expected answers were;

(a) Types of Ignition coils

• Can/oil filled type
• Core/laminated iron core type
• Ignition block
• Pencil/coil-on-plug ignition coil
• Ignition coil park system 
• Single ignition coil
• Double/dual ignition coil
• Magneto ignition coil
• Solenoid ignition coil

                                                                            
(b)Advantages of battery ignition system

• It is cheap.
• Sparking is good at low speed.
• Starting of engine is easier.
• Used in cars, buses and trucks.
• It is not affected by adjusting spark timing.
• It is durable.

                                       
(c) (i) Properties of a contact breaker in an ignition system

• Contact points must open and close at the correct time
• Noise should not be produced in operation
• Points should not be oxidized or corroded.
• Ability to withstand high temperature
• Good conductor of electricity.

                                                                        
(ii) Factors that determine the thermal capacity of a plug

• Insulator nose length
• Electrode material
• Thread contact length
• Projection of electrode
• Heat range