Question

What is the function of the ignition coil which is simply a transformer?

(a) Step up the current

(b) Step down the current

(c) Step down the voltage

(d) Step up the voltage

This question was addressed to me during an interview.

Question is taken from Types of Ignition System in chapter Conventional Ignition System of Automotive Engine Design

Answer 1

Correct answer is (d) Step up the voltage

For explanation I would say: The ignition coil is simply a transformer with certain characteristics making it suitable for its special use but impairing to some extent its efficiency as a transformer. It serves to set up the low battery voltage to high voltage.