Magnetism and Matter — Chapter Summary

A bar magnet has two poles

A bar magnet has two poles, North and South. The poles always occur together, and cutting a magnet gives two smaller magnets, each with both poles. An

Magnetic field lines of a magnet

Magnetic field lines of a magnet or solenoid form continuous closed loops. The tangent at any point gives the direction of the magnetic field, and a d

A current

A current-carrying finite solenoid produces a field pattern similar to a bar magnet. At large distances, its axial field has the same form as that of

A magnetic dipole in a uniform

A magnetic dipole in a uniform magnetic field experiences torque given by τ = m × B and magnitude τ = mB sinθ. The dipole tends to align with the fiel

The potential energy of a magnetic

The potential energy of a magnetic dipole in a uniform field is U_m = -m · B = -mB cosθ. It is minimum at θ = 0° and maximum at θ = 180°. The zero of