The rule that determines the direction of a magnetic field produced around a straight conductor carrying current is:

The correct answer is Right-hand thumb rule.

Key Points

• The Right-hand thumb rule is used to determine the direction of the magnetic field around a straight conductor carrying current.
• According to the rule, if you hold the conductor in your right hand with the thumb pointing in the direction of the current, the curl of your fingers represents the direction of the magnetic field lines.
• This rule is a simple and practical way to visualize the magnetic field created due to the flow of electric current.
• It is commonly applied in physics to understand the relationship between current flow and the generated magnetic field around a straight conductor.
• The magnetic field around the conductor forms concentric circles, which can be identified using this rule.

Additional Information

• Fleming's Left-Hand Rule:
  • This rule is used to determine the direction of force experienced by a current-carrying conductor placed in a magnetic field.
  • It relates the direction of current, magnetic field, and force using the thumb, forefinger, and middle finger of the left hand.
• Fleming's Right-Hand Rule:
  • This rule is used to determine the direction of induced current when a conductor moves in a magnetic field.
  • It relates motion, magnetic field, and induced current using the thumb, forefinger, and middle finger of the right hand.
• Magnetic Field:
  • A region around a magnetic material or a current-carrying conductor where magnetic forces can be detected.
  • Field lines are used to represent the magnetic field, and they form closed loops.
• Applications of Right-Hand Thumb Rule:
  • Used in designing electrical instruments like solenoids and electromagnets.
  • Helps in understanding the magnetic effects around current-carrying wires in practical applications.