Final answer:
In a balanced three-phase electrical supply, all of the following are equal: phase currents, phase voltages, and phase winding impedances. This means consistent voltage and current are delivered from power lines and electrical generators.
Step-by-step explanation:
When a three-phase electrical supply is generated, what are considered equal are the phase voltages and the phase currents, provided that the system is balanced.
This means that the same voltage applies to each phase and the same current flows in each phase. In an ideal three-phase system, the phase winding impedances are also designed to be equal to maintain balance.
Therefore, the correct answer is: All of the above are equal in a properly designed three-phase electrical supply system.
It is important to note that three-phase electrical supply is commonly used for transmitting voltage from power lines for use in homes and businesses due to its efficiency in delivery and the consistent power it provides.
The current from the power lines and the current from the electrical generator are both crucial in this context as they involve the flow of electric charge that powers appliances and equipment.