Question

What does the direction of thumb indicate in the right-hand thumb rule? In what way this rule is different from Fleming’s left-hand rule?

Answer 1

Thumb indicate in the thumb rule:

In the right-hand rule, the thumb held by curled fingers indicates the direction of the current, whereas, in the left-hand rule, the force experienced by a current-carrying conductor placed in an external magnetic field is indicated.

Differences between Left-hand rule and right-hand rule:

Left-Hand Rule	Right-Hand Rule
1.John Ambrose Fleming invented it.	It was invented by John Ambrose Fleming
2. It is used for electric motors.	It is used for electric generators
3. The purpose of the rule is to find the direction of motion in an electric motor.	The purpose of the rule is to find the direction of induced current when a conductor moves in a magnetic field.
4. The thumb represents the direction of the thrust on the conductor.	The thumb represents the direction of motion of the conductor.
5. The index finger represents the direction of the Magnetic Field.	The index finger represents the direction of the Magnetic Field.
6. The middle finger represents the direction of the current.	The middle finger represents the direction of the induced current.