Electrical Installation Waec Answers 2024
(2a)
(i) Lead dioxide (PbO2)
(ii) sponge lead (Pb)
(iii) sulfuric acid (H2SO4).
(2aii)
(i) Local action: Occurs when impurities in the lead plate react with the electrolyte, causing self-discharge and reducing battery capacity.
(ii) Polarization: Happens when hydrogen gas bubbles form on the negative plate, hindering the chemical reaction and reducing battery efficiency.
(2aiii)
(i) Low voltage output.
(ii) Diminished electrolyte level.
(iii) Reduced specific gravity of the electrolyte.
(2b)
(2bi) Parts of a high breaking capacity fuse:
(i) Fuse element
(ii) Fuse holder
(2bii)
(i) Enhanced safety by quickly interrupting high fault currents, preventing damage to equipment and potential hazards.
(ii) Increased reliability by effectively protecting electrical circuits from overcurrent conditions.
(iii) Versatility in various applications due to the ability to handle high fault currents without nuisance tripping.
Electrical Installation
(3a)
(i) Core
(ii) Windings
(iii) Commutator
(iv) Shaft
(3b)
(i) Yoke: Provides a path for the magnetic flux, supporting the field poles and armature.
(ii) Brush: Conducts current between stationary wires and moving parts, such as the commutator in a DC generator.
(3c)
(i) Insulation resistance test
(ii) Continuity test
ELECTRICAL INSTALLATION*
01-10: AADACCABAB
11-20: BBCADACCAA
21-30: BADACABBDA
31-40: ACACABBACA
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