calculate the self-induction coefficient for the coil that can be connected in series to
an electric lamp the resistance of its filament is 44Ω and electric source of frequency
42Hz and emf 220V so that the filament does not melt even if it does not stand for
more than 4A

a) (0.125 H)
b) (0.315 H)
c) (0.525 H)