Question

What is the magnetic field inside a long air-core solenoid?

Options

• \[B=\mu_0nA\]

• \[B=\mu_0n^2I\]

• \[B=\mu_0nI\]

• \[B=\frac{\mu_0I}{n}\]

Answer 1

The field depends on permeability \[\mu_0\], turns per unit length \[n\], and current \[I\]. Their product gives \[B=\mu_0nI\].