Exam-style question
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A coil with 150 turns experiences a change in magnetic flux of 0.4 Wb over a period of 2 seconds. What is the induced emf? Scenario focus: magnetic fields in a distinct A-Level Physics fields context; identify the field quantity, source, direction, and unit before selecting the answer.
- A.30 V
- B.20 V
- C.10 V
- D.15 V
Model answer
What a good answer should say
- 30 V
Explanation
Why this works
The correct answer is 30 V. This is correct for Magnetic fields because the stem is testing magnetic fields; the chosen option keeps the field quantity, source interaction, direction, and unit consistent.
The alternatives are weaker because they mix gravitational, electric, magnetic, orbital, or transformer ideas, or they attach the right number to the wrong physical meaning.
Common mistake
No common mistake is linked to this question yet.