A straight current-carrying conductor is placed in a uniform magnetic field. Under what condition is the force experienced by the conductor the greatest? What is the force when the conductor is placed parallel to the magnetic field?
Generated by claude-sonnet-4-6 · 2026-06-26 01:12 · grounding rag
Model Answer
Condition for greatest force: The force on a current-carrying conductor is greatest when the direction of current is perpendicular (at right angles) to the direction of the magnetic field.
Force when parallel to the field: When the conductor is placed parallel to the magnetic field, the force experienced by it is zero.
Source: Chapter 12, Section 12.3 — Force on a Current-Carrying Conductor in a Magnetic Field
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Explanation
- The textbook explicitly states: "the displacement of the rod is largest when the direction of current is at right angles to the direction of the magnetic field."
- When conductor is parallel to field, the angle between them is 0°, so no force acts (this follows from F = BIL sinθ; sin 0° = 0, though the formula itself is not required at Class 10 level — just state the result).
- Examiners expect both parts answered clearly. Missing either part loses a mark.