Discuss the magnetic field produced around a straight current-carrying conductor. State and explain the rule by which the direction of the lines of force of the magnetic field around a current-carrying conductor can be determined.

The magnetic field produced around a straight current-carrying conductor is a circular field that surrounds the wire. The direction of the magnetic field lines is determined by the current flowing through the conductor and can be described using Ampère’s Circuital Law.

Magnetic Field Around a Straight Conductor:

When an electric current flows through a conductor (such as a wire), it creates a magnetic field around it. The magnetic field lines form concentric circles around the conductor. The strength of the magnetic field is proportional to the current flowing through the conductor and inversely proportional to the distance from the conductor.

Rule for Determining the Direction of Magnetic Field (Right-Hand Rule):

To determine the direction of the magnetic field lines around a straight current-carrying conductor, the Right-Hand Rule is commonly used. Here’s how it works:

  1. Right-Hand Rule for a Straight Conductor:

    • Imagine holding the conductor in your right hand.
    • Point your thumb in the direction of the current (the direction of positive charge flow).
    • The direction in which your fingers curl around the conductor represents the direction of the magnetic field lines.

    In simple terms, if you place your right thumb along the wire in the direction of current flow, your fingers will curl around the wire in the direction of the magnetic field.

Explanation of the Field:

  • The magnetic field around a straight conductor is circular and lies in planes perpendicular to the wire.
  • The field strength decreases with increasing distance from the wire.
  • The magnetic field is stronger near the conductor and becomes weaker as you move further away.

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