1. Name the metal used to manufacture the coiled spring below - NSC Agricultural Technology - Question 2 - 2021 - Paper 1

1. Vesconite gives long life with low maintenance and low friction.
2. It remains hard in water, not softening or seizing.
3. Vesconite is dimensionally stable, meaning it maintains its shape and size.

1. All-weather clothing.
2. Eyeglass lenses.
3. Teflon tape for plumbing.

The critical melting point of Teflon is approximately 327 °C.

1. Copper is a good conductor of heat and electricity.
2. It does not rust or corrode easily.
3. It can be easily joined by soldering.
4. Copper is flexible and durable.

1. Brass resists metal fatigue better than steel.
2. It has low-friction properties, enhancing performance.
3. Brass is less prone to corrosion from seawater.
4. It is ideal for applications requiring durability.

1. In explosive atmospheres where sparks must be avoided.
2. In the presence of flammable vapours to prevent igniting them.

The resin used in glass fibre products is typically a synthetic polymer that hardens upon curing, providing structural integrity and flexibility.

1. Glass fibre is lightweight, making it easier to handle and transport.
2. It is easily repaired when broken, extending the lifespan of the boat.
3. Glass fibre offers strength and toughness, ensuring durability against harsh conditions.

The earth return system allows electric current to complete its circuit through the ground, ensuring that there is an effective path for the return current, thus making the fence operational.

1. A break in the wire circuit due to wear or damage.
2. Poor grounding or connection issues in the electric fence system.

To test the earth system, first ensure that all connections are secure. Then, use an electric fence tester to measure the voltage, adjusting the grounding system as necessary to maintain proper function.