2.1 Indicate the alloy metal that is specifically used to manufacture the following products and give TWO reasons why the metal is used: 2.1.1 Milk tanks 2.1.2 Fittings for hot-water copper pipes 2.1.3 Hammering tools that can be used in explosive atmospheres 2.2 Name TWO hot-working processes that can be used to change the structural properties of brass - NSC Agricultural Technology - Question 2 - 2018 - Paper 1

Brass is the alloy metal used for fittings in hot-water copper pipes. This material is favored due to its excellent strength, machinability, wear resistance, hardness, and corrosion resistance, ensuring durability and longevity in plumbing applications.

Bronze, specifically beryllium copper, is utilized for manufacturing hammering tools in explosive atmospheres. Its properties include a low spark, low friction, and resistance to corrosion, which are crucial for safety in volatile environments.

Two hot-working processes that can change the structural properties of brass are annealing and tempering. Annealing helps relieve stresses and improve ductility, while tempering optimizes the hardness and strength of the material.

Farmers prefer fibreglass troughs because they are lightweight and easier to move around, making repairs and adjustments convenient. Additionally, fibreglass is rust-resistant, ensuring a longer lifespan compared to concrete, which can deteriorate over time.

The resin used in fibreglass production is a low viscosity fluid that can be transformed into tough, flexible solids by adding a hardening agent. This quality allows for the creation of durable fibreglass products suitable for various applications.

Two methods used to join fibreglass parts are using a pop rivet and bolting the pieces together. Fibreglass can also be bonded using adhesive techniques designed for composite materials.

Vesconite is ideal for various marine applications because it does not swell or seize in water, retains its hardness, has low friction properties, is corrosion resistant, and does not contain harmful asbestos. Additionally, it allows for easy machining, which is beneficial for customized applications.

To ensure sufficient cohesion when applying an adhesive, first, the surface should be cleaned properly to remove any contaminants. If the surface is slippery, it should be sanded to increase texture. A thin base coat of adhesive should be applied to enhance adhesion. Only a thin layer of adhesive should be used for better bonding, and it's essential to apply adhesive to both surfaces involved.

When testing the earth system of an electric fence, the first step is to short out the live fence line to the ground. Next, switch the energizer on and measure the voltage between the ground and the earth spike with a meter. If the measured voltage exceeds 200 volts, it indicates that the earth installation may be inefficient.

Electric fences are commonly used on farms for protection and farm security purposes, as well as for temporary fencing solutions or to contain dangerous animals.

Three alternative energy sources that can supply energy to an electrical fence include wind energy, solar power, and water energy.