Exam-style question
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If a magnetic field strength of 0.2 T is applied to a coil with 50 turns and the magnetic flux changes by 0.1 Wb, what is the induced emf if this change occurs in 5 seconds? Scenario focus: field energy in a distinct A-Level Physics fields context; identify the field quantity, source, direction, and unit before selecting the answer.
- A.0.4 V
- B.1 V
- C.2 V
- D.4 V
Model answer
What a good answer should say
- 0.4 V
Explanation
Why this works
The correct answer is 0.4 V. This is correct for Magnetic fields because the stem is testing field energy; 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.