Give me an example Calculate: $($a$)$ the number of turns required for an

inductor to absorb $230$ V on a $50$ Hz circuit; $($b$)$ the

length of airgap required if the coil is to take a magnetizing

current of $3$ A $($r$.$m$.$s$.)$; $($c$)$ the phase difference

between the current and the terminal voltage. Mean

length of steel path, $500$ mm; maximum flux density in

core, $1$ T; sectional area of core, $3000$ mm$2$; maximum

magnetic field strength for the steel, $250$ A$/$m; core

loss, $1\mathrm{.}7$ W$/$kg; density of core, $7800$ kg$/$m$3.$ Neglect

the resistance of the winding and any magnetic leakage

and fringing. Assume the current waveform to be

sinusoidal.of