Final answer:
The current required to deliver 15 MW of power at a voltage of 120 V is 125,000 A. This is impractical for real-world distribution, hence high voltage transmission is used to reduce current.
Step-by-step explanation:
The student has asked about the current required to deliver 15 MW of power at a voltage of 120 V. To find the current (I) required to deliver a certain amount of power (P), we can use the formula P = IV, where V is the voltage. Given that the voltage (V) is 120 V and the power required (P) is 15 MW, which is 15,000,000 watts, we can rearrange the formula to solve for I: I = P/V. Therefore, the current I is 15,000,000 W / 120 V, which equals 125,000 A.
Using hig currents like 125,000 A at low voltage is impractical and dangerous due to the enormous amount of heat generated and the large conductors required, which is why electricity is usually transmitted at high voltages and lower currents over long distances.