Basic Electricity 2, WASSCE (SC), 2017

Question 6

 

  • State three safety precautions that are observed during the repair of electrical appliances.
  • An electric iron plugged into a live socket outlet did not heat up.
  • State three likely causes of the fault.
  • State two types of test that can be used to investigate the fault.
  • List two instruments that can be used for the repair.

Observation

The expected answers were;

(a)       Safety precautions to be observed during repair of electrical appliances       

  • Follow manufacturer’s safety manual / precautions / regulations
  • Avoid touching any bare conductor or terminal in any appliance connected to a    

      voltage source

  • Avoid carrying out repair work on any appliance connected to a voltage source.
  • Use appropriate tools
  • Carry out repairs in a well illuminated environment
  • Wear safety goggles and gloves (Personal Protective Devices/ Equipment)
  • Avoid repair when wet

                                                                   
(b)      (i) Likely causes of electric iron not heating up

  • open circuit / blown fuse.
  • poor contact
  • faulty thermostat
  • faulty element                                              

            (ii)  Types of test to investigate fault

  •  voltage test
  • continuity / open circuit test

                                                                                                                                 
(iii)  Instruments to be used for the repair

  • Screwdrivers
  • Voltmeter / multimeter switched to voltage range
  • Ohmmeter/ multimeter            
  • Long nose plier         

          Many candidates who attempted this question did not do the question well.