Question

A resistance of 20 Ω, a capacitance of 80 μF and an inductor of 50 mH are connected in series. This combination is connected across a 220 V ac supply of variable frequency. When the frequency of supply equals the natural frequency of the circuit, calculate : (1) angular frequency of supply (2) impedance of the circuit

Define coefficient of self-induction. Obtain an expression for self-inductance of a long solenoid of length l, area of cross-section A having N turns.

Calculate the self-inductance of a coil using the following data obtained when an AC source of frequency (200/π) Hz and a DC source is applied across the coil.