Right-hand rule

Definition

The right-hand rule is a mnemonic used to determine the direction of the magnetic field surrounding a current-carrying conductor. Point your thumb in the direction of the current and curl your fingers; your fingers indicate the direction of the magnetic field lines.

5 Must Know Facts For Your Next Test

1. The right-hand rule applies to straight conductors, loops, and solenoids.
2. For a straight wire, curling fingers around it with the thumb pointing along the current shows the magnetic field encircling the wire.
3. Reversing the current direction reverses the magnetic field direction.
4. Magnetic fields form concentric circles around a straight wire carrying an electric current.
5. The strength of the magnetic field decreases with increasing distance from the wire.

Review Questions

• How does reversing the current in a straight wire affect its magnetic field?
• Describe how to use the right-hand rule for determining the direction of a magnetic field around a straight conductor.
• What shape do magnetic field lines take around a thin, straight wire carrying a steady current?

Related terms

Magnetic Field: A vector field surrounding magnets and electric currents, where forces due to magnetism can be observed.

Electric Current: The flow of electric charge carried by moving electrons in a conductor.

$\mu_0$ (Permeability of Free Space): $\mu_0$ is a physical constant that describes how much resistance is encountered when forming a magnetic field in vacuum.