Current, Ohm’s Law and Power

Current is how much charge flows past a point per unit time and is measured in amperes. The rate of flow of current is controlled by the voltage and the resistance. Batteries supply voltage and current in one direction, called direct current. Resistance is determined by the physical properties of the conductor: the material it is made of, the length and the cross-sectional area. Resistance is measured in Ohms. Ohm’s Law states that for an ideal resistor, the ratio of voltage to current is constant. Power is the rate of energy consumption or production. You can find power by multiplying current and voltage. Resistors dissipate energy, converting electrical energy to thermal energy. The power company charges you for how much electric energy you use.