Answer to Question #118787 in Electricity and Magnetism for Adeyinka Samuel

Question

The magnetic flux density at the centre 100 loop circular coil of 15cm diameter can be the same as to the magnetic flux density at the end of a 200 turns 500cm long solenoid with a current of 3A. estimate the magnitude of current that must flow through circular coil for this to happen (Take permeability of the free space as 4π × 10–7 H/M

Answer 1

Magnetic flux density is measured by $\mu_o \frac NlI$

equating for both we get

$\frac{100}{15}\times I=\frac{200}{500}\times3$

$I=0.18 A$