Which of the following rules is used to determine the direction of the force on a currentcarrying conductor in an electric motor?

Correct option is D

The correct answer is option (d)Fleming’s Left-Hand Rule

The rule used to determine the direction of the force on a current-carrying conductor in an electric motor is:

Fleming's Left-Hand Rule

Fleming's Left-Hand Rule states that if you align your left hand as follows:

• Thumb: Points in the direction of the force (motion).
• Forefinger: Points in the direction of the magnetic field.
• Middle finger: Points in the direction of the current.

Information booster :

Fleming's Right-Hand Rule :

Fleming's Right-Hand Rule is used to determine the direction of induced current in a conductor moving in a magnetic field. Fleming's Right-Hand Rule is primarily used in generators to determine the direction of current generated in a conductor.​

• Thumb: Indicates the direction of motion of the conductor (or the force acting on it).
• Forefinger: Indicates the direction of the magnetic field.
• Middle finger: Indicates the direction of the induced current.

Ampere's Law:

Ampere's Law states that the line integral of the magnetic field (B) around a closed loop is proportional to the net current (I) passing through the loop. Mathematically, it is expressed as:

​$$\oint \mathbf{B} \cdot d\mathbf{l} = \mu_0 I_{\text{enc}}$$​​

where:

• $$\mathbf{B}$$​ : Magnetic field
• $$d\mathbf{l}$$​: Infinitesimal element of the closed loop
• $$\mu_0​$$​: Permeability of free space (4\pi \times 10^{-7}
• $$I_{\text{enc}}$$​: Net current enclosed by the loop

Right-Hand Thumb Rule

• The Right-Hand Thumb Rule helps determine the direction of the magnetic field around a current-carrying conductor.
  If you hold a straight current-carrying conductor in your right hand with the thumb pointing in the direction of the current, then the fingers curled around the conductor indicate the direction of the magnetic field lines.

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