Voltage, current and resistance
Measure current and voltage, and use Ohm's law, V = I × R.
Planned. This module is part of the plan and is not written yet.Handled with care: read the note under Practicalities before using this module.
Why it matters
Choosing the right resistor so an indicator LED doesn't burn out, or understanding why a long thin cable gets warm, starts with Ohm's law.
Draft outline · in review- For
- Level 8–9 · JSS 2 to JSS 3 (BECE)
- Inside
- 5 lessons and a test · about 75 minutes
- Topic
- Electricity · core, 2 of 4
Inside the module.
5 lessons in order, about 75 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: Current, voltage and resistance
What each one measures, in amps, volts and ohms.
Explain15 min, from minute 0
Lesson 2: Measuring with a multimeter
Measure current in series and voltage in parallel, with real meters or the simulator.
Lab20 min, from minute 15
Lesson 3: Ohm's law
V = I × R, and rearranging it to find I or R.
Explain10 min, from minute 35
Lesson 4: Finding the unknown
Use two known quantities to find the third.
Worked example15 min, from minute 45
Lesson 5: Ohm's law problems
Mixed problems, with units.
Practice15 min, from minute 60
End-of-module test
Measure or simulate current and voltage, and use Ohm's law to find an unknown quantity.
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 75 min
Practicalities
Draft outline · in reviewHandle with care
Experiments use low-voltage batteries only, never mains electricity. The facilitator's safety notes come first.
Built to run offline
Planned to run on the Lantern's own computer, with no internet needed.
Beyond the screen
Needs materials
Materials
A battery pack of 3–6 V (AA cells in a holder), Insulated wires with crocodile clips, Two or three resistors, for example 100 Ω and 220 Ω and A multimeter
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
A 9 V battery is connected across a 450 Ω resistor. What current flows?
Work it out on paper first, then show the answer and mark it yourself.
Particulars
Where it sits
What a learner can do after it
- Measure or simulate current and voltage in a circuit.
- Use Ohm's law, V = I × R, to find an unknown quantity.
Needs first
We suggest first (never a lock)
Level
Level 8–9 · JSS 2 to JSS 3 (BECE)
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 75 minutes
Alignments
- Aligned to WASSCEpartial · in reviewWASSCE Physics syllabus: current electricity, Ohm's law
- Aligned to GCSEpartial · in reviewGCSE Physics: electricity, potential difference, current and resistance (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
On these pathways
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 · the destination Needs Circuits and current (required), Substituting into formulae (recommended).
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.