The main function of the ignition system in a spark-ignition (SI) engine is to:
B
Supply air-fuel mixture
C
Ignite the air-fuel mixture
Analysis & Theory
Ignition system ignites the compressed air-fuel mixture in SI engines.
Which component generates a **high voltage** for the spark plug?
Analysis & Theory
The ignition coil converts 12V battery power into high voltage for the spark plug.
The device that **distributes high voltage** to spark plugs is called:
Analysis & Theory
Distributor sends high-voltage pulses to spark plugs in the correct firing order.
Which component in the ignition system produces the **spark**?
Analysis & Theory
The spark plug creates a spark to ignite the air-fuel mixture.
Battery ignition system is commonly used in:
C
Four-stroke petrol engines
Analysis & Theory
Battery ignition is widely used in four-stroke petrol engines.
Magneto ignition system is mainly used in:
B
Motorcycles and scooters
Analysis & Theory
Magneto systems are simple and used in 2-wheelers and small engines.
In a battery ignition system, the primary source of energy is:
Analysis & Theory
Battery provides the primary electrical energy in battery ignition systems.
Function of the **ignition coil** is to:
Analysis & Theory
Ignition coil boosts the 12V battery to 10,000+ volts for ignition.
Which component controls the **timing** of the spark?
Analysis & Theory
Distributor ensures each spark plug fires at the correct crankshaft position.
The **spark gap** is located in which component?
Analysis & Theory
The spark gap is the space between the electrodes of a spark plug.
A magneto produces voltage using:
C
Permanent magnet and coil
Analysis & Theory
Magneto generates electricity using a rotating magnet and a coil.
Which ignition system is **self-contained** and does not need a battery?
Analysis & Theory
Magneto system generates its own power and is independent of a battery.
Electronic ignition systems offer better performance due to:
Analysis & Theory
Electronic systems give accurate spark timing, improving efficiency and power.
Breaker points in conventional ignition systems serve to:
B
Break the primary circuit
Analysis & Theory
Breaker points open and close to interrupt the primary coil current.
The capacitor (condenser) in an ignition system is used to:
C
Prevent arcing at breaker points
Analysis & Theory
The condenser absorbs voltage spikes and reduces arcing at the breaker points.
The **rotor** in the distributor is responsible for:
C
Distributing high voltage to plugs
Analysis & Theory
Rotor rotates and connects the high voltage coil output to the correct spark plug.
Which ignition system has **no mechanical contact points**?
Analysis & Theory
Electronic ignition uses solid-state devices, eliminating wear-prone contact points.
The advantage of magneto ignition is:
B
Self-generation of electricity
D
Needs frequent maintenance
Analysis & Theory
Magneto systems generate electricity themselves, good for remote or small engines.
Which of the following is NOT a part of a spark ignition system?
Analysis & Theory
Fuel injector is part of fuel system, not the ignition system.
In SI engines, ignition occurs due to:
Analysis & Theory
SI (spark-ignition) engines rely on spark plugs for combustion initiation.
Battery ignition systems are less preferred in two-wheelers because:
B
They require a heavy battery
D
They produce weak spark
Analysis & Theory
Battery ignition systems require a battery, which adds weight and complexity.
The **primary winding** in an ignition coil:
C
Is connected to the spark plug
D
Receives current from battery
Analysis & Theory
Primary winding receives 12V current from the battery for voltage conversion.
The **secondary winding** of an ignition coil has:
Analysis & Theory
The secondary winding has more turns to generate high voltage.
Spark plug gap is typically around:
Analysis & Theory
The correct spark plug gap is usually between 0.7 and 1.0 mm.
Which system gives **more consistent ignition** over time?
Analysis & Theory
Electronic ignition is more reliable as it lacks mechanical wear-prone parts.
The **ignition switch** in a vehicle is used to:
B
Activate the ignition system
Analysis & Theory
Turning the ignition switch powers the ignition circuit.
Which ignition system is preferred in **racing and performance vehicles**?
Analysis & Theory
Electronic ignition offers precision and high performance, ideal for racing.
In a magneto system, spark strength depends on:
Analysis & Theory
Magneto output increases with engine speed.
The **HT lead** in ignition systems connects:
A
Fuel pump to spark plug
D
Distributor to fuel tank
Analysis & Theory
HT (High Tension) lead carries high voltage from the coil to the spark plug.
Advancement in ignition systems now uses:
A
CDI (Capacitor Discharge Ignition)
Analysis & Theory
CDI systems provide quick, powerful sparks using capacitor discharge.