Question

1. the workings of a digger (excavator) bucket is described as follows. (1)

(illustration from: technology today grade 7 – mml)
a three linked lever systems are used to move the bucket and boom.
b a pneumatic system is used to move a linked lever system of three levers to move the bucket and the boom
c a hydraulic system is used to move a linked lever system of two levers to move the bucket and boom
d a hydraulic system is used to move three linked lever systems to move the bucket and the boom

1. magnets with the same poles pointing towards each another will. (1)

a attract each another
b repel each another
c both a and b
d nothing will happen

1. the structure below is made stable by... (1)

a the strong joints
b the wide base
c the steel used to make the structure
d triangulation

1. how are the following components connected in this circuit. (1)

a parallel
b series
c both a and b
d only a

1. what would the result be in the circuit below, if one of the lightbulbs broke. (1)

a both lightbulbs would die
b the other lightbulb will still glow
c the other lightbulb will get dimmer
d the other lightbulb will be more brighter

1. the correct systems diagram for the circuit below is. (1)

Explanation:

20. Step1: Identify excavator mechanism

Excavators use hydraulic pressure to actuate a set of three linked levers (boom, dipper stick, bucket) to move the working parts.

21. Step1: Recall magnet pole rule

Like magnetic poles exert a repulsive force on one another.

22. Step1: Recall structural stability

Triangulation adds rigid triangular shapes to a structure, preventing deformation and making it stable.

23. Step1: Analyze circuit connection

The two components have separate paths from the power source, which is a parallel circuit configuration.

24. Step1: Use parallel circuit property

In a parallel circuit, each component has an independent power path. If one bulb fails, current flows through the other bulb's path.

25. Step1: Trace circuit energy flow

The circuit uses a battery (input electrical energy), the circuit conducts electrical energy (process), and the bulb outputs electrical energy converted to light/heat, matching option D's energy sequence.

Answer:

1. D. A hydraulic system is used to move a linked lever system of three levers to move the bucket and the boom
2. B. Repel each another
3. D. triangulation
4. A. Parallel
5. B. The other lightbulb will still glow
6. D. INPUT: Electrical energy, PROCESS: Electrical energy, OUTPUT: Electrical energy