Question 1
- Define the following terms:
- conductor.
- insulator.
-
- List five insulating materials.
- List five conducting materials
-
- Define the term soldering.
- State four functions of flux in soldering.
-
Draw the B. S. graphical symbols for each f the following electrical components
- core inductor.
- resistor.
- capacitor.
- circuit breaker.
- earth electrode.
Observation
In part (a), candidates’ performance was good. Many candidates were able to respond correctly.
In part (b), performance was good.
In part (c), many candidates were able to define soldering and functions of soldering.
In part (d), performance was fair. Many candidates found it difficult to draw- core inductors, circuit breakers, and earth electrodes.
The expected answers include:
-
-
- Conductor
A conductor is any material that offers very low resistance to the flow of electric current.
OR
A conductor is any material that allows the passage of electricity/electric current to flow through it.
- Insulator
An insulator is any material that offers (very) high resistance to the flow of current.
OR
An insulator is any material that does not allow the passage of electricity/electric current to flow through it.
-
-
- Insulating Materials.
- Rubber
- Paper
- Ceramics
- Cloth (dry)
- Mica
- PVC
- Ebonite
- (fire) Clay
- Wood
- Glass
- Asbestos
- Oil
- Porcelain
- Ceramics.
- Plastics
- Sand/block/stone.
- Leather.
- Silk.
- Cotton.
- Micanite
- Slate
- Conducting Materials.
- Copper.
- Aluminium.
- - Silver.
- Gold.
- Bronze.
- Water (Solution).
- Iron.
- Lead.
- Zinc.
- Sodium.
- Tin.
- Brass.
- Soldering
- Functions of flux in Soldering
- Cleaning agent.
- Reduces the resistance of the joints/conductors.
- Remove oxide film from the surface.
- Provides easy flow of solder.
- Remove grease/oil from the surface.
- Prevent oxide from reforming.
Soldering is the process of joining two or more non-ferrous metals together with the use of heat and solder.
OR
Soldering is the process of joining two or more metals together by melting and flowing a filler metal (solder) into the joint.
OR
Soldering is the process of joining two or more conductors/metals together using heat and solder.
British Standard (B.S) Graphical Symbols.
