cExams.net
Do You Know
Questions & Answers on General Knowledge.

Question:
How does current flow and return in a home electric hot water heater? I only see two black hot wires and no white return wire.
Answer:
Your hot water heater is powered by 240 volt electric power through the two black wires. Each black wire is hot, meaning that its voltage fluctuates up and down significantly with respect to ground. In fact, each black wire is effectively 120 volts away from ground on average, so that if you connected a normal light bulb between either black wire and ground, it would light up normally. However, the two wires fluctuate in opposite directions around ground potential and are said to be "180° out of phase" with one another. Thus when one wire is at +100 volts, the other wire is at -100 volts. As a result of their out of phase relationship, they are always twice as far apart from one another as they are from ground. That's why the two wires are effectively 240 volts apart on average. Most homes in the United States receive 240 volt power in the form of two hot wires that are 180° out of phase, in addition to a neutral wire. 120-volt lights and appliances are powered by one of the hot wires and the neutral wire, with half the home depending on each of the two hot wires. 240-volt appliances use both hot wires.
--- >>>
More Questions:
  • Which hair grows the fastest?
  • What is the difference between the magnetic and electric ballasts used in fluorescent lights?
  • Why are lasers harmful to your eyes?
  • If heat rises, how come snow accumulates on mountains? Why is it colder up there instead of down here?
  • What is a season?
  • Why do some objects bounce off the ground (balls) whereas others would break (eggs)?
  • Can you suggest an experiment to prove that a helium balloon floats because helium is lighter than oxygen?
  • How does steam work?
  • Why is the Moon's surface filled with craters?
  • How do anti-lock brake systems work?
  • Why is cheating on corporate accounting ledgers called “cooking the books”?
  • Why do we define the rat race as “keeping up with the Joneses”?
  • How fast is the earth moving through space? Does this movement affect our perception of time?
  • How does a magnetic train work? How can I make an experiment with it for a school project?
  • Which city is the smallest?
  • How many times does the heart beat?
  • I enjoy watching the pole-vaulters at the Olympics, especially Daly Thompson. Could you explain the physics of the pole vault for me?
  • What effect does ice have on potholes?
  • My grandmother used to have this watch she wound by shaking it. How is it possible?
  • Which mammal spends the most time sleeping?
  • Why is the Andromeda galaxy so special?
  • What led to the Renaissance?
  • Is there any way to make a homemade fog machine, like they use in clubs?
  • What is gravitational force?
  • Why are batteries different sizes (e.g., AAA, AA, C, and D) if they all have 1.5 volts?
  • Beautiful National Parks Around the World
  • Valentines Day Class Room Party Ideas
  • Tips for Valentines day Gift
  • Prevent Dengue
  • Benefits of Lactuca
  • Dotnet Interview Q&A

  • Chourishi Systems