Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: Recall and use the equation for e.m.f. E = W / Q
Learning Objective/s:
  • Recall the definition of electromotive force (e.m.f.) and its relationship to work and charge.
  • Explain the difference between e.m.f. and terminal potential difference, including the effect of internal resistance.
  • Apply the equation E = W / Q (and related forms) to calculate e.m.f. in numerical situations.
  • Use the relationship E = P / I to connect power, current and e.m.f.
  • Solve practice problems involving work, charge, current, and internal resistance.
Materials Needed:
  • Projector or interactive whiteboard for slides and equations.
  • Worksheet with practice questions and space for calculations.
  • Batteries, resistors, ammeter and voltmeter for a simple circuit demonstration.
  • Calculators (one per student or shared).
  • Whiteboard and markers.
  • PDF handout summarising definitions, formulas and example calculations.
 Introduction:
Begin with a quick demonstration of a battery lighting a small lamp and ask students what property of the battery makes the current flow. Review prior knowledge of work, charge and voltage. State that by the end of the lesson they will be able to recall the definition of e.m.f., distinguish it from terminal potential difference, and correctly use the equation E = W / Q.
Lesson Structure:
  1. Do‑now (5') – Short question on work and charge from the previous lesson.
  2. Mini‑lecture (10') – Define e.m.f., present E = W / Q, discuss units and the relation Terminal p.d. = E – I rint.
  3. Guided derivation (10') – Work through the forms E = W/(I t) and E = P / I on the board.
  4. Hands‑on demonstration (15') – Set up a simple circuit with a battery, internal resistance, ammeter and voltmeter; measure terminal p.d. and compare with e.m.f.
  5. Practice problem solving (15') – Students complete worksheet questions in pairs while the teacher checks calculations.
  6. Concept check (5') – Quick exit‑ticket quiz with one problem on e.m.f. versus terminal p.d.
Conclusion:
Summarise that e.m.f. is the work per coulomb under open‑circuit conditions and that internal resistance reduces the terminal potential when current flows. Have students write a one‑sentence note describing the key difference as a retrieval check. Assign homework: additional problems calculating e.m.f. and terminal p.d. from given data.