Formulas to Remember

Here are some more formulas related to the Biot-Savart law and the magnetic fields produced by current-carrying wires:

Magnetic field of a straight wire: The magnetic field at a point (P) a distance (r) from a long, straight wire carrying a current (I) is given by:

B=μ0I2πr

where ((\mu_0)) is the permeability of free space.

Magnetic field of a circular loop: The magnetic field at the center of a circular loop of radius (R) carrying a current (I) is given by:

B=μ0I2R

Magnetic field of a solenoid (long, thin coil): The magnetic field inside a solenoid is given by:

B=μ0nI where (n) is the number of turns per unit length of the solenoid.

Magnetic force between two parallel wires: The force between two long, parallel wires carrying currents (I_1) and (I_2) separated by a distance (d) is given by:

F=μ0I1I22πd where (\mu_0) is the permeability of free space.

Magnetic torque on a current loop: The torque exerted on a current-carrying loop of area (A) placed in a uniform magnetic field (B) is given by:

τ=μ×B

where (\overrightarrow{\mu}) is the magnetic dipole moment of the loop, given by:

μ=IA

These formulas provide additional tools for calculating magnetic fields and forces in various scenarios involving current-carrying wires and coils.



Table of Contents