Which of the following is used to study the direction of rotation of a coil in a magnetic field in an electric motor?

Correct option is D

The correct answer is (D)  ​Fleming’s left hand rule

• ​Fleming's left-hand rule helps determine the direction of motion or force on a current-carrying conductor placed in a magnetic field, such as in an electric motor.
  
• This rule is a simple method to find the direction of force when the current and magnetic field directions are known.
• When a current flows through a coil in a magnetic field, a force is exerted on the coil, causing it to rotate continuously.
• Stretch your left hand so that the thumb, index finger, and middle finger are perpendicular to each other.
• The index finger points in the direction of the magnetic field.
• The middle finger indicates the direction of current.
• The thumb represents the direction of the force or motion.

Information booster:

• This rule helps find the direction of induced current in a conductor moving in a magnetic field.
• Stretch your right hand so that the thumb, index finger, and middle finger are perpendicular to each other:
• Thumb: Direction of motion of the conductor.
• Index Finger: Direction of the magnetic field.
• Middle Finger: Direction of the induced current.
• This rule is used in electric generators.

​Right hand thumb rule

• This rule is used to determine the direction of the magnetic field around a current-carrying conductor.
• Point your right-hand thumb in the direction of the current.
• The curled fingers around the conductor show the direction of the magnetic field.
• It is used in understanding the magnetic effects of current.