Question

The magnetic field inside a long solenoid is given by which of the following formulas?

Options

• \(B = \mu_0 n I\)

• \(B = \frac{\mu_0 I}{2\pi r}\)

• \(B = \frac{\mu_0 n I}{2}\)

• \(B = \frac{\mu_0 N I}{2\pi r}\)

Answer 1

The magnetic field inside a long solenoid is \(B = \mu_0 n I\), where \(\mu_0\) is the permeability of free space, \(n\) is the number of turns per unit length, and \(I\) is the current. The other options represent the field due to a straight conductor, the field at the ends of a solenoid, and the field inside a toroid, respectively.