Cambridge International AS & A Level Physics · A2 21 · structured
Induced e.m.f. in a microphone coil
Alternating currents and induction · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- discriminating
- Marks
- 6
- Topics
- 3
- Answer
- Complete
Question6 marks
A microphone coil has 220 turns, each of area 2 × 10⁻³ m². A uniform magnetic field perpendicular to the coil changes by 0.45 T in 0.065 s. Calculate the magnitude of the average induced e.m.f.
Task interpretation
What a complete response should do
Build a visible chain from the information given to the quantity or statement requested.
Make assumptions explicit, connect several ideas, and test whether the final result is physically reasonable.
- Response type
- structured
- Allocation
- 6 marks
- Demand
- discriminating
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