Subtopic: I.C. engine systems – fuel, cooling, lubrication, ignition, electrical, intake and exhaust
Question Statement:
In a conventional distributor-type battery ignition system, the 'dwell angle' is defined as:
Options:
(A) The angle of distributor shaft rotation during which the breaker contact points remain closed to allow primary coil current to saturate
(B) The angle of spark advance before top dead center
(C) The duration of the high-voltage spark discharge across the spark plug gap
(D) The crank angle between intake valve opening and closing
Answer Key:
A
Step-by-Step Solution & Explanation
Dwell angle (or cam dwell) is the number of degrees through which the distributor cam rotates while the breaker points are in closed contact. This closed period allows magnetic energy to build up in the ignition coil primary winding before the points open to trigger the spark.