Right-Hand Rule for Force on Current-Carrying Wire

Steps:

• Assume current flows left to right along the wire.
• Assume magnetic field points upward, perpendicular to the wire.
• Point fingers in current direction, curl toward field direction.
• Thumb indicates force direction: into the page.

Why C is correct:

• The vector formula F = I L × B yields force into the page when current is horizontal rightward and field is vertical upward, per the right-hand rule.

Why the others are wrong:

• A: Matches force if field direction were reversed (downward).
• B: Matches force if current direction were reversed (right to left).
• D: Matches force if both current and field were reversed simultaneously.

Final answer: C