$6$:$21$

:$!!.$

TRY QUEST$-$MEE SYSTEMS...

$17.$ With the aid of a sketch, explain how six $(6)$ semi$-$conductor diodes could be arranged to rectify a $3-$phase ac supply to a dc source.

$18.$ How do you test a diode to certify that it is good or defective.

$19.$ If one diode in the excitation system of a brushless synchronous generator fails, briefly describe two $(2)$ likely consequences on the generator.

$20.$ Describe how the kW load can be divided between two alternators running in parallel.

$21.$ Using Fleming's Right Hand Rule, state and explain briefly, the three $(3)$ factors necessary for an electrical generator to generate electrical power.

$22.$ Reference FIG. $1.$ below: Identify all the component parts that together constitute the rotor and briefly explain the function of each part.

FIG. $1.$ syumer$-$cage al iviotur nutur

$23.$ What is the meaning of:

a$).$ 'flashing'

b$).$ 'excitation'

c$).$ 'residual magnetism'

as associated with the operation of an alternator?

$24.$ Why is it essential to know if the phase sequence of the incoming shore supply is 'correct'?

$25.$ Reference FIG. $2.$

Identify all the arrowed parts and briefly explain the function of monh mont