Final answer:
The question centers on the concept of electrical impedance in a simple AC circuit, involving a negligible line impedance and a load phase impedance of 20 - j8 Ohms.
Step-by-step explanation:
The question pertains to the concept of impedance in an electrical circuit, specifically dealing with the phase impedance of the load and the relationship between voltage and current. In the context provided, a simple circuit schematic is described in which the impedance of the lines between the source and load is considered negligible. It is also given that the phase impedance of the load is 20 - j8 Ohms, indicating that there is both resistance (real part) and reactance (imaginary part) in the load. When a voltage, V, with an angle of O, is applied across the load, the phase angle between voltage and current can be deduced from the impedance. This phase angle indicates how much the current lags or leads the voltage, which is a critical concept in AC circuits as it affects power factors and circuit behavior. Figure 20.8 further emphasizes the simplicity of the circuit by stating that it contains a single voltage source and a single resistor, and that the resistance of the wires (if any) can be included in the total resistance R of the circuit. The fluctuation of the potential difference V in an AC voltage source, as mentioned in figures 20.15 and 20.20, and represented by the mathematical expression V = Vo sin 2πft, underscores the alternating nature of the voltage in such circuits.