All Problems Electric Oscillations
Problem 4.120
A long one-layer solenoid tightly wound of wire with re sistivity \(\rho\) has \(n\) turns per unit length. The thickness of the wire insulation is negligible. The cross-sectional radius of the solenoid is equal to \(a\). Find the phase difference between current and alternating voltage fed to the solenoid with frequency \(v\).
4.120. The current lags behind the voltage by phase angle \(\varphi,\) defined by the equation \(\tan \varphi=\frac{\mu_{0} \pi^{2} v a}{4 n \rho}\).