Electrical Power, Energy & Circuit Design — Drills · Grade 12 Science
Chapter: Electricity, Magnetism & CircuitsWhat these drills covers
By the end of Electrical Power, Energy & Circuit Design you should be able to:
- I can calculate component power and energy with correct circuit values.
- I can distinguish efficiency, kilowatt-hours, and source internal losses.
2 questions, numeric and written answer, each with a worked explanation.
Vocabulary used: kilowatt-hour, internal resistance, emf.
Problem 1
A9 V component draws.20 A. Find power.
Hints
Write the relationship first; substitute with consistent units.
Answer and explanation
1.8 W
P=VI.
Problem 2
Is a kWh power or energy?
Answer and explanation
Energy; it is power multiplied by time.
Response criteria
- State a scientifically accurate conclusion.
- Show the calculation or mechanism that supports it.
- Include units, conditions, or limits where relevant.