Multimeters

A multimeter or a multitester, also known as a VOM (Volt-Ohm meter), is an electronic measuring equipment that combines several measurement functions in one unit. A typical multimeter would include basic features like the ability to measure voltage, current, and resistance. A multimeter is a good device to have in order to test things like radios, light switches, flashlights, cars, etc. Batteries can be tested with a multimeter because the energy emitted from a battery or electrical device can be measured in volts or ohms.  Its good to know how to make basic measurements at home with your electrical equipment.  Most common multimeters sell for less than $ 5, for the basic ones to be used around the house.  More expensive meters don’t exactly have more features. They just have better accuracy for professional work, and they are more concentrated on their construction and durability.

Energy Use and Project Plans

Hawaii ranks #1 in electric energy costs today. 46.3 million barrels of petroleum were imported for Hawaii's total energy use over the past year.
That's 36 barrels of petroleum for every man, woman and child living in Hawaii. There was $5.09 billion left the state last year to pay for imported petroleum. That is $4,000 for every person living in Hawaii.
That's kind of like buying 10 million roundtrip tickets to Las Vegas. Also, there was 11.3 million barrels of petroleum burned by the Hawaii utilities last year to make electricity.
11.3 million barrels of petroleum x $79/barrel=$893 million. That would pay a year's tuition for the 13,952 undergraduate students at the University of Hawaii at Manoa 8 times. The average residential meter in Hawaii uses 615 kilowatt hour per month
That's $175/month spent on electricity - enough for 20 Zip Paks, 24 boxes of a dozen malasadas or 14 pounds of fresh poke. The point is that we use, burn, and waste a lot of energy here in Hawaii each year. In my physics class right now we are trying to find a way for people to save energy in their homes. If we don’t use luxury things like televisions and A/C as much then our electricity use will decline.  I predict that by reducing the use of television daily, we would be able to save a great deal of power.   I predict that by not using the A/C and fans I will save electricity.  My prediction is that I will cut my electricity bill by at least 8%.

Series & Parallel Cicuits

A series circuit is a circuit in which resistors are arranged in a chain, so the current has only one path to take. The current is the same through each resistor. The formula to find the total resistance in a series circuit is R_EQ = R₁ + R_2. A parallel circuit is a circuit in which the resistors are arranged with their heads connected together, and their tails connected together. The current in a parallel circuit breaks up, with some flowing along each parallel branch and re-combining when the branches meet again. The voltage across each resistor in parallel is the same. In a series circuit, every device must function for the circuit to be complete. One bulb burning out in a series circuit breaks the circuit. In parallel circuits, each light has its own circuit, so all but one light could be burned out, and the last one will still function.

PC: hyperphysics.phy-astr.gsu.edu

Ohms Law

Ohm's law is named after a German Physicist Gerog Simon Ohm.  Ohm's law shows a direct relationship between the voltage applied to an object and the resulting current.  Its used in finding resistance and the formula that goes with the law is V=IR which is electric current = voltage / resistance. Ohm is the unit of resistance. Electric Power is a complete electric circuit that represents rate at which energy is converted from the electrical energy of moving charges to another form.  Power equals the rate at which energy is utilized.  Watts is the units of power.  The equation is P = VI (Power = energy converted / time = voltage x charge / time = voltage x charge / time = current x voltage).  Where Watts = Joules / second.

This not so great quality picture I took when I went to las vegas. It is of the roller coaster New York New York. Without electricity none of this would have been running.

Electricity

What is electricity?

Electricity is the flow of electrical charge.  Its an energy carrier, so it gets it is energy from other sources of energy.  The nucleus contains protons and neutrons.  Electrons surround the nucleus.  When there is a balancing force between protons and electrons, they can gain or lose an electron.  When an electron is lost, an electric current develops, which then electricity can be developed.

Why is electricity important?

Electricity is used in almost everything we do! Our society and the way that we live our lives today wouldn’t be able to function without electricity. Our phones, our laptops the two things that we use most these days would not be able to function without electricity. It is an essential to our lives today.

What is electric current?

Electric current is electricity flowing through a conductor.  The flow of electricity creates a current, which is measured in amperes. It is flow of electric charges through a surface at the rate of one coulomb per second. I=Q/t (Q=charge t=time)

What is resistance?

Resistance is the hindrance to a flow of charge through wires and external circuits.  Through the course of the electrons flow, they come across a delay in their movement, which is the resistance.  More collisions or stopping points in the movement of the electrons means there is more resistance.