If we want to receive an FM station that broadcast on frequency = 100 MHz and we have to build a tunning circuit of LC utilizing a capacitor of 10pF. Design an inductor L to make tune by using your plastic Pin as a core for widing. Assume your pin diameter is 1 cm and wire of 0.8 mm diameter.
use L = μ0N^2r^2/2ρ0
n^2 = N^2 l^2