Auto mechanics Paper 2 WASSCE (PC 2ND), 2019

Question 5

 

    1. What is dwell angle, as applied to contact breaker?
    2. List two tools used for adjusting contact breaker gap.

    1. Name the types of plug shown in fig. 4.
    2. State one advantage of using Plug X over plug Y, as applied to automobile engines.

  1. Explain how spark plug gap is checked.
    1. State one purpose of automobile coil ignition system.
    2. Why is it necessary to make lead cable from coil distributor thicker than other cables in the ignition system?

 

Observation

 

The candidates that attempted this question did that very well. However, a few of them could not adequately answer 5(d)(ii). The solution of the poorly answered aspect of the question is as given below.

    1. Why Lead Cable from Coil Distributor is Thicker than Other Cables in Coil Ignition System

      Lead cable from coil to distributor is made thicker than other ignition system cables for the purpose of:
      - preventing leakage of current/voltage;
      - carrying the high current/voltage;
      - withstanding under-bonnet dampness which causes leakage of high tension current/voltage;
      - avoiding burning of cable (quick starting)