Physics

Problem

State the correct expression for the magnetic field

B

at the centre of a very long air-cored solenoid having turn density

n

(turns per metre) and carrying current

I

. a)

B = \dfrac{\mu_0 n I}{2\pi}

B = \mu_0 n^{2} I

B = \mu_0 n I

B = \dfrac{\mu_0 I}{n}