Science — CBSE Class 10 board question

(i) Right-Hand Thumb Rule:
Imagine holding a current-carrying straight conductor in your right hand such that the thumb points in the direction of current. Then the fingers wrapping around the conductor indicate the direction of the magnetic field lines around it.

(ii) Fleming's Left-Hand Rule:
Stretch the thumb, forefinger, and middle finger of the left hand mutually perpendicular to each other. If the forefinger points in the direction of the magnetic field and the middle finger points in the direction of current, then the thumb points in the direction of the force (motion) on the conductor.

Source: Chapter 12, Sections 12.2.2 and 12.3

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• This is a standard 3-mark question: 1 mark for naming + stating rule (i), 1 mark for naming + stating rule (ii), 1 mark for correctness/clarity overall.
• Do not confuse the two rules: Right-Hand Thumb Rule → direction of magnetic field; Fleming's Left-Hand Rule → direction of force.
• Bold key terms (thumb, forefinger, middle finger, directions) to make the answer scannable for examiners.
• A small diagram of Fleming's Left-Hand Rule, if time permits, can earn you bonus clarity marks.