Observation

The expected responses were;

(a)      Substation : It is a load center for receiving, transmitting and distributing electrical energy via power transformers .                                                           
(b)      Busbars:  These are the main bars or connections which offer convenient means of connecting switches and other equipment into various arrangements.         
(c)      Transformers: A transformer at the substation converts the incoming supply voltage to a lower or higher value which is fed either to the substation or distribution feeders.
(d)     Feeder:  This conducts power from a substation to load/consumer end.         
(e)      Circuit Breaker:  An automatic device for interrupting the flow of current in an electric  
circuit as a safety measure.

Many candidates who attempted this question did not do well.