WAEC ELECTRICITY ANSWERS 2022

Here is the waec basic electricity answers 2022

(2ai)

The instantaneous value is “the value of an alternating quantity (it may ac voltage or ac current or ac power) at a particular instant of time in the cycle”.

(2aii)

The root mean square (RMS) value is the effective value of a varying voltage or current. It is the equivalent steady DC (constant) value which gives the same effect.

(2b)

Check the image below

6ai

*Rewirable*

I. Rewirable fuse has the advantages of replacement of fuse element without any risk. ii. The cost of the replacement is also very less

*Catrige*

i. It has a high breaking capacity.

ii. There is no risk of reclosing after the trip.

iii. It has good selectivity values

*6bi. PIPE EARTHING*: A galvanized steel perforated pipe is buried vertically, connecting all the electrical conductors to the ground where the depth of the pipe depends on the soil conditions. Pipe earthing is an economical type of earthing compared to other earthing methods.

*6bii.PLATE EARTHING*: A plate made up of galvanized copper or iron is buried vertically at a depth of not less than 3m from ground level. The plate here connects all the conductors to the earth.

(5a)

(i) Line support: It is used maintain adequate clearance between energized conductors and the ground

(ii) Stay: Stays are used for the termination of the lateral forces by making the pole support in angle.

(iii) Cross arms are used mainly for supporting and holding the Conductors and insulators.

(5b)

(i) Radial distribution system

(ii) Parallel feeders distribution

(iii) Ring main distribution system

(iv) Interconnected distribution

(6a)

(i) ADVANTAGES OF REWIRABLE FUSE

– It requires minimum time to replace.

– It has current limiting effect.

(ii) ADVANTAGES OF CARTRIDGE FUSE

– It has a high breaking capacity.

– There is no risk of reclosing after the trip.

(6b)

(i) Pipe Earthing :

A galvanized steel-based pipe is placed vertically in a wet is known as pipe earthing, and it is the most common type of earthing system. The pipe size mainly depends on the soil type and magnitude of the current.

(ii) Plate Earthing:

In this type of system, a plate is made up of copper or GI (galvanized iron) which are placed vertically in the ground pit less than 3meters from the earth. For a better electrical grounding system, one should maintain the earth moisture condition around the plate earthing system.