Year 9 Science · Unit 3 · Lesson 14
Foundation Worksheet
Learning Goals
Match each grid component to its function
Draw a line connecting each component on the left to its correct function on the right. Or write the matching letter next to each component.
| Grid Component | Your answer | Function |
|---|---|---|
| Generator | A. Steps voltage up from generation levels to transmission levels (275–500 kV) | |
| Step-up transformer | B. Carries electricity at very high voltage over long distances with low losses | |
| Transmission line | C. Converts mechanical energy into electrical energy at the power station | |
| Step-down transformer | D. Reduces voltage from transmission levels to levels safe for homes (~240 V) | |
| Distribution network | E. Carries electricity at lower voltages through local streets to homes and businesses | |
| AEMO | F. The organisation that manages electricity dispatch to keep supply and demand balanced across the NEM |
Fill the gap
Choose the correct word from the word bank to complete each sentence about why electricity is transmitted at high voltage.
When a power station generates electricity, a step-up increases the to hundreds of thousands of volts. This reduces the flowing through the wires. Because power in wires depends on current squared multiplied by resistance (P = I²R), lowering the current dramatically reduces the energy wasted as heat during . The (National Electricity Market) connects Queensland, New South Wales, Victoria, South Australia and Tasmania on one grid. The organisation (Australian Energy Market Operator) manages the dispatch of electricity to keep supply and demand balanced at all times.
1. Explain in your own words why power lines carry electricity at 330,000 V rather than at 240 V (the voltage in your home).
2. Which Australian state or territory is NOT connected to the National Electricity Market (NEM)? Why might this be the case?
Wrap Up
In one sentence, what was the main idea of this lesson?