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Fleming's right hand rule

Fleming's right hand rule helps find the direction of induced current when a conductor moves in a magnetic field.

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Student-friendly explanation

Stretch the thumb, forefinger, and middle finger of the right hand mutually perpendicular to each other. The forefinger points in the direction of magnetic field, the thumb points in the direction of motion of the conductor, and the middle finger shows the direction of induced current. This rule is especially useful in generators and induction-based questions.

How to write this in exams

  1. 1

    Start with the exact idea

    Fleming's right hand rule helps find the direction of induced current when a conductor moves in a magnetic field.

  2. 2

    Then show how to use it

    1. Use the right hand. 2. Stretch thumb, forefinger, and middle finger at right angles. 3. Point forefinger along magnetic field. 4. Point thumb along motion. 5. Middle finger gives induced current direction.

  3. 3

    Add one concrete example

    If a conductor moves upward in a magnetic field from north to south, the right hand rule gives the direction of the induced current in the conductor.

  4. 4

    Avoid this incomplete answer

    A common wrong answer is to use the left hand, which belongs to force on current, not induced current.

Definition

Fleming's right hand rule helps find the direction of induced current when a conductor moves in a magnetic field.

Example

If a conductor moves upward in a magnetic field from north to south, the right hand rule gives the direction of the induced current in the conductor.

Rule to remember

Forefinger = magnetic field, thumb = motion of conductor, middle finger = induced current, all at right angles.

Memory hook

Right hand gives induced current.

Examples and method

Worked example

A wire moving to the right in a magnetic field may produce current upward, depending on field direction. The right hand rule helps determine that current direction quickly in exam problems.

Method to apply

1. Use the right hand. 2. Stretch thumb, forefinger, and middle finger at right angles. 3. Point forefinger along magnetic field. 4. Point thumb along motion. 5. Middle finger gives induced current direction.

Diagram support

Draw a right hand with three perpendicular fingers labelled field, motion, and induced current.

How CBSE asks it

State the rule, determine induced current direction, or connect the rule to a generator.

Avoid common mistakes

Common confusion

Students often use the left hand here or mix the directions of motion and current.

Common wrong answer

A common wrong answer is to use the left hand, which belongs to force on current, not induced current.

Exam tip

Right hand is for induced current; left hand is for force in motor questions.

Quick check

In Fleming's right hand rule, what does the middle finger show?

The middle finger shows the direction of induced current in the conductor when it moves in a magnetic field.

Answer writing and exam use

1-mark answer

Fleming's right hand rule helps find the direction of induced current when a conductor moves in a magnetic field.

2-mark answer

Fleming's right hand rule helps find the direction of induced current when a conductor moves in a magnetic field. Forefinger = magnetic field, thumb = motion of conductor, middle finger = induced current, all at right angles. If a conductor moves upward in a magnetic field from north to south, the right hand rule gives the direction of the induced current in the conductor.

3-mark answer

Stretch the thumb, forefinger, and middle finger of the right hand mutually perpendicular to each other. The forefinger points in the direction of magnetic field, the thumb points in the direction of motion of the conductor, and the middle finger shows the direction of induced current. This rule is especially useful in generators and induction-based questions. Forefinger = magnetic field, thumb = motion of conductor, middle finger = induced current, all at right angles. A wire moving to the right in a magnetic field may produce current upward, depending on field direction. The right hand rule helps determine that current direction quickly in exam problems. State the rule, determine induced current direction, or connect the rule to a generator. A common wrong answer is to use the left hand, which belongs to force on current, not induced current.
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