Exam-style question
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A charged particle experiences a magnetic force of 5.0×10⁻¹⁴ N while moving at 1.0×10⁶ m s⁻¹ in a 0.25 T field. What is the radius of its circular path if the magnetic force is the centripetal force? Scenario focus: gravitational fields in a distinct A-Level Physics fields context; identify the field quantity, source, direction, and unit before selecting the answer.
- A.0.10 m
- B.0.20 m
- C.0.30 m
- D.0.40 m
Model answer
What a good answer should say
- 0.20 m
Explanation
Why this works
The correct answer is 0.20 m. This is correct for Magnetic fields because the stem is testing gravitational 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.