i need help
2007-02-14 12:38:56 · 5 answers · asked by DP 2 in Science & Mathematics ➔ Engineering
what da ya wanna know ?
2007-02-14 12:42:57 · answer #1 · answered by sammy 5 · 0⤊ 0⤋
What aspect do you need to understand?
I will explain voltage, current and resistance.
Voltage (measured in volts) is the unit of electrical potential difference between two points. For example, there is a voltage between a live wire and the ground, and between the positive and negative terminals of a battery.
Current (measured in amperes) is the actual flow of electricity through some path. Current flows from positive to negative potentials. What actually happens is electrons move from negative to positive, but do not less this confuse you--current is defined as electrical flow from postitive to negative.
Resistance (measured in Ohms) is the property of a material to resist the flow of current. For example, a copper wire has very low resistance and current flows easily, so it is called an conductor. Wood, glass, and rubber on the other hand are insulating (high resistance) materials and electric current will not flow through them easily.
The relationship between these three properties is
Voltage = Current x Resistance (Ohms' Law).
This means that the current resulting from applying a certain voltage across some object is indirectly related to the resistance, i.e. if you apply ten volts to the copper wire (low resistance) you get a much higher current than if you apply ten volts to a stick of wood (high resistance).
2007-02-14 12:53:00 · answer #2 · answered by Anonymous · 0⤊ 0⤋
One advantage of electrical energy is that it can control ,store and converted easily.Electricity is connected with the atomic structure of substances.If there are more free electrons in the outermost orbit of an atom, it may be a good conductor of electricity.Electric current only flows when a charge difference occurs between two points(say positive and negative).Also,there should be a closed path for the current flow.
2007-02-14 15:05:14 · answer #3 · answered by salim h 2 · 0⤊ 0⤋
Line up some marbles. Push the end one, and watch the one on the other end move. With electricity, electrons are doing the same thing. Unless you subscribe to the "hole flow" theory, that holes move, not electrons.
2007-02-14 13:31:16 · answer #4 · answered by jimbo 2 · 0⤊ 0⤋
Check: http://science.howstuffworks.com/electricity.htm.
2007-02-14 12:44:04 · answer #5 · answered by Ace Librarian 7 · 0⤊ 0⤋