Identify the safety mechanism indicated by arrow A in the drawings below - NSC Agricultural Technology - Question 5 - 2016 - Paper 1

The component used on the three-point mechanism to prevent the implement from swinging sideways is the stabilising chains.

To set the horizontal levelness of the implement, the top link of the three-point hitch must be adjusted.

The component on the tractor that allows for adjustment of the cross angle of the implement is the levelling box.

When storing the hay rake for a long period, the following maintenance procedures should be followed:

1. Lubricate and grease all moving components to prevent rust.
2. Check all bearings for wear and replace if necessary.
3. Inspect all broken rake teeth and repair or replace as needed.

1. Ram or piston type - Produces rectangular bales.
2. Roller type - Produces cylindrical bales.

Component A is the removable warning lights or brake lights, component B is the safety emblem/triangle, and component C is the reflectors/indicators or reverse lights.

It is advisable NOT to drive on a public road with an abnormally wide load during:

1. After daylight hours (at night).
2. In poor visibility conditions (fog, rain).
3. In bad weather conditions (rainy or windy) or during peak hours with high vehicle traffic.

Three mechanical problems that can occur during the use of a combine harvester include:

1. Loss of maize kernels due to improper settings.
2. Thresher belt becoming too hot or breaking.
3. Blockages in the system that lead to halts in operation.

Three major causes of metal fatigue on a hammer mill are:

1. Vibration due to excessive speeds or unbalanced hammers.
2. General wear of the metal components over time.
3. Rust due to exposure to moisture or inadequate maintenance.

The component on a tractor that activates the control valve of the hydraulic system is the operator's control lever.

Using the formula: Na × Da = Ng × Dg Where:

• Na = 25 (revolutions per minute of drive pulley)
• Da = ? (diameter of drive pulley)
• Ng = 100 (revolutions per minute of driven pulley)
• Dg = 100 mm (diameter of driven pulley)

Thus, we can substitute: 25 × Da = 100 × 100 25 × Da = 10,000 Da = 10,000 / 25 Da = 400 mm

Hence, the diameter of the drive pulley is 400 mm.

If the V-belt is crossed, the turning direction of the driven pulley will be anti-clockwise.

Three disadvantages of using V-belts in drive systems include:

1. V-belts are more difficult to install than flat belts.
2. They are not normally manufactured in long lengths, limiting application.
3. V-belts cannot be joined easily which can lead to inefficiencies.

Three factors to consider before purchasing a new tractor are:

1. Driving power (Kw).
2. Local availability of parts and service.
3. Rigidity of construction.

Two advantages of mechanisation for agriculture include:

1. Increased profits or productivity.
2. Reduced work load on labourers.

A. Pneumatic B. Hydraulic C. Pneumatic D. Hydraulic