Question

What is the magnetic field at the centre of the outer large coil when it carries current \[I_2\] ?

Options

• \[B_2=\frac{2\mu_0I_2}{r_2}\]

• \[B_2=\frac{\mu_0I_2}{2r_1}\]

• \[B_2=\frac{\mu_0I_2}{2r_2}\]

• \[B_2=\mu_0n_1I_1\]

Answer 1

The current \[I_2\] in the outer coil produces a field at its centre. For radius \[r_2\] , that field is \[B_2=\frac{\mu_0I_2}{2r_2}\] .