Direct and alternating current
Why batteries give d.c., homes use a.c., and an inverter turns one into the other.
Planned. This module is part of the plan and is not written yet.
Why it matters
The Lantern's panels and battery give direct current, but its computers and air conditioners run on alternating current. The inverter in between makes that work.
Draft outline · in review- For
- Level 10–11 · SSS 1 to SSS 2
- Inside
- 5 lessons and a test · about 60 minutes
- Topic
- Electricity · core, 2 of 4
Inside the module.
5 lessons in order, about 60 minutes in all, then a short test. Learners go at their own pace; the minutes are a guide, not a timetable.
Draft outline · in review
Lesson 1: Direct current
Current that flows one way, from cells, batteries and solar panels.
Explain10 min, from minute 0
Lesson 2: Alternating current
Current that reverses many times a second: 230–240 V at 50 Hz in homes across the four Lantern countries.
Explain15 min, from minute 10
Lesson 3: Comparing the graphs
Plot d.c. and a.c. against time in a simulation.
Investigate10 min, from minute 25
Lesson 4: What an inverter does
Switching d.c. back and forth electronically to make a.c.
Explain15 min, from minute 35
Lesson 5: Check your skills
Match sources and appliances to d.c. or a.c.
Review10 min, from minute 50
End-of-module test
Compare direct and alternating current, and explain what an inverter does and why solar systems need one.
Mastered at 85% or more. Retake it until you pass; nothing is lost, and each try gives feedback.
Already know it? A Challenge Test (planned) clears the whole module: 90% overall, no objective below 75%.
Last stageafter about 60 min
Practicalities
Draft outline · in reviewBuilt to run offline
Planned to run on the Lantern's own computer, with no internet needed.
Languages
Planned first in English; every module aims to reach all of the Lantern's languages.
Try a question.
One question from the module, as a learner would meet it. Have a go, then open the worked solution a step at a time.
Draft outline · in review
Why does a solar-powered building need an inverter?
Particulars
Where it sits
What a learner can do after it
- Compare direct and alternating current.
- Explain what an inverter does and why solar systems need one.
Needs first
Level
Level 10–11 · SSS 1 to SSS 2
Level mappings are approximate. A qualified teacher or lecturer in each country must check them before they appear in the app.
Difficulty for its level
2 of 4 · Core
Time
About 60 minutes
Alignments
- Aligned to GCSEpartial · in reviewGCSE Physics: direct and alternating potential difference (descriptive ref)
Alignment in review until a qualified teacher or lecturer checks it. No exam body, university or vendor endorses us; learners still sit the real exam.
Challenge Test
Planned: a Challenge Test to prove you know it and skip it. Pass at 90% overall, with no objective below 75%.
University courses it previews
Physics, Electrical Engineering, Mechanical Engineering, Medicine and Surgery
The route here.
Everything this module builds on, drawn as a route from its foundations. Solid lanes must be mastered first, or cleared by a Challenge Test; dashed lanes are suggestions that never lock anything.
- MA-ALG-FRM-01Substituting into formulaeMaths · JSS 1 to JSS 2 (Level 7–8) · Planned · recommended
- SC-PHY-ELC-01Circuits and currentSciences · JSS 1 to JSS 2 (Level 7–8) · Planned
- SC-PHY-ELC-02Voltage, current and resistanceSciences · JSS 2 to JSS 3 (BECE) (Level 8–9) · Planned Needs Circuits and current (required), Substituting into formulae (recommended).
- SC-PHY-ELC-03Electrical power and energySciences · JSS 3 (BECE) to SSS 1 (Level 9–10) · Planned Needs Voltage, current and resistance (required), Substituting into formulae (recommended).
- SC-PHY-ELC-05Direct and alternating currentSciences · SSS 1 to SSS 2 (Level 10–11) · Planned · the destination Needs Electrical power and energy (required).
Help light the room where this is learned.
Every route on this map starts in a classroom with 24 stations, a tutor that works offline and a facilitator upstairs. Four are planned and waiting for light.