Observation

This is a popular question among the candidates.
In part (a), majority of the candidates were able to highlight sources of danger to an electrician in an electrical workshop.
In part (b), majority of the candidates could not draw a well labelled diagram to illustrate the wiring of two points of light in parallel, controlled by a one-way switch.
In part (c), majority of the candidates were able to list tools used for surface wiring in an electrical installation work.
In part (d), majority of the candidates could not define the terms earthing and earth electrode.
>The expected answers are:

1. (i)

   SOURCES OF DANGER IN AN ELECTRICAL WORKSHOP
   - ineffectiveness of earth continuity conductor
   - use of cable without mechanical protection / bare conductor
   - use of cable without proper insulation / damaged insulation
   - working on live conductors
   - use of unearthed brass / unskirted lamp holders
   - lack of protective covering on switches / boxes
   - cable run over sharp edges
   - water and chemical
   - overloading of circuit
   - use of wrong tools
   - non-insulated tools
   - horseplay
   - lack of safety wear
   - moving machinery
   - poor ventilation/illumination
   - slippery floors
   

   (ii) CAUSES OF ELECTRIC SHOCK
   - wet hands
   - walking bare footed
   - frayed cables / incorrect jointing of cables
   - un-insulated / badly made connections
   - use of cable without mechanical protection
   - unprotected or unearthed socket outlets/plugs
   - poor or broken earth connections

   (iii) PROCEDURES FOR RESCUING AN ELECTRIC SHOCK VICTIM
   - switch off the source of current / supply (before attempting to remove the casualty)
   - remove any obstructions to breathing
   - pull off the person by his clothing / using an insulated material
   - carry out artificial respiration
   - send for a doctor / medical help

2. ILLUSTRATION OF A TWO POINTS OF LIGHT
3. TOOLS FOR SURFACE WIRING
   - hammer
   - knife
   - raw plug
   - saw
   - pliers
   - screw driver
   - neon tester / test lamp
   - gimlet
   - stripper
   - measuring tape
   - plumb line
   - chisel
4. (i) I : it is the connection of an electrical installation to the general mass of the earth

   OR

   it is a means of connecting all metallic parts of an installation to the general mass of the earth
   II it is the conductor connected to the earthing lead and buried in the ground

   OR

   it is a metal rod, providing effectual connection with the general mass of the earth. (ii)CALCULATION OF THE CURRENT FLOWING THROUGH A CIRCUIT