Final answer:
To operate a 4.00-kW electric clothes dryer, 40 people would be needed, and an 800 MW power plant would require 8 million people. For 400-Hz AC power, as used in military aircraft, one complete cycle takes 2.5 milliseconds. The question about generator emergency power testing lacks context and cannot be answered without specific regulatory references.
Step-by-step explanation:
Understanding Power Output and Generator Frequency
Concerning the question of how many people it would take to run a 4.00-kW electric clothes dryer, we start by recognizing that one person can output 100 W of power. Therefore, to run a clothes dryer that requires 4 kW (or 4,000 W), you would need 4,000 W / 100 W per person = 40 people.
When considering replacing the power output of a large electric power plant that generates 800 MW, we see that it would take an incredible amount of human power to match this output. Specifically, 800 MW equals 800,000,000 W, and dividing this by the 100 W that a single person can produce, we find that it would take 8 million people to generate that amount of power.
For the question regarding military aircraft using 400-Hz AC power and the time for one complete cycle, we can use the formula for the period of a wave which is T = 1/f, where T is the period and f is the frequency. Therefore, the time for one cycle at 400 Hz is T = 1/400 seconds, which simplifies to 2.5 milliseconds for one complete cycle.
The question of frequency of generator emergency power testing seems to lack enough context for a definitive answer here, as it doesn't align with the provided informational context about power output from human energy or electrical generators in general. It would be advisable to refer to specific regulatory requirements or manufacturer's guidelines for the correct frequency of testing for emergency power systems in generators.