ELECTRICITY
Voltage- Voltage is a measure of energy carried by a charge; it is the energy per unit charge. The proper name for voltage is potential difference. Voltage is supplied by the battery or power supply. It is this energy that makes the electrical current flow in a circuit by pushing the electrons around. Voltage is used up in the components of a circuit not the wires. Voltage is measured in Volts. It is measured with a voltmeter and is connected in a parallel circuit. The unit voltage is shown as ‘V’.
Current- Current is the rate of flow of a charge. It is not used up; it flows into a component and then flows out. Current is measured in amps or amperes. It is measured with an ammeter and is connected in series. The symbol ‘I’ is used to show current.
Characteristics of the sources of electricity that can be fatal.
Currents of approximately 0.06 to 0.07 Amps are potentially fatal, depending on the person and the type of current. This is because they can make the heart beat in an uncontrolled manner. A person can feel 1 milliamp, 5 milliamps is painful to a person, above 15 milliamps a person loses muscle control and 70 milliamps can be fatal. The amount of damage done by electric shock depends on the amount of the current, but also which part of the body the electricity flows through.