Exam-style question
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A straight conductor carrying a current of 5 A experiences a force of 0.2 N when placed in a magnetic field. If the length of the conductor in the magnetic field is 0.5 m, calculate the magnetic flux density. Scenario focus: inverse-square reasoning in a distinct A-Level Physics fields context; identify the field quantity, source, direction, and unit before selecting the answer.
Model answer
What a good answer should say
- The magnetic flux density B can be calculated using the formula B = F / (I × L).
- Substituting the values, B = 0.2 N / (5 A × 0.5 m) = 0.2 N / 2.5 A = 0.08 T.
Explanation
Why this works
The correct answer is The magnetic flux density B can be calculated using the formula B = F / (I × L). This is correct for Magnetic fields because the stem is testing inverse-square reasoning; 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.