Question

Name and state the rule to determine the direction of a:
(i) magnetic field produced around a current carrying straight conductor.
(ii) force experienced by a current carrying straight conductor placed in a magnetic field which is perpendicular to it.

Answer 1

Section (i): Magnetic Field Surrounding a Straight Current-Carrying Conductor:
The Right-Hand Rule dictates the direction of the magnetic field produced by a current-carrying straight conductor. To apply it:
- Orient your right thumb in the direction of the current through the conductor.
- The direction indicated by your curled right-hand fingers represents the magnetic field lines around the conductor.
Consequently, the magnetic field forms concentric circles centered on the wire, with the current at its core.
Section (ii): Force on a Straight Current-Carrying Conductor in a Magnetic Field:
Fleming's Left-Hand Rule determines the direction of the force acting on a straight current-carrying conductor placed within a magnetic field. Its application is as follows:
- Extend your left thumb, forefinger, and middle finger perpendicular to each other.
- Align your forefinger with the magnetic field direction (B) and your middle finger with the current direction (I).
- Your thumb will then indicate the direction of the force (F) exerted on the conductor.
This rule is instrumental in identifying the force exerted on a conductor situated in a magnetic field.