Question

For an air (or vacuum) core, which permeability is used in the solenoid derivation?

Options

• \[\mu_r\] alone

• \[\Phi_B\]

• \[n\]

• \[\mu_0\]

Answer 1

An air (or vacuum) core uses the permeability \[\mu_0\]. The magnetic-core expression additionally includes relative permeability \[\mu_r\].