What is Electricity???

Electric Charge Matter has both positive and negative particles (protons and electrons) Matter has both positive and negative particles (protons and electrons) Gaining or losing electrons produces a net charge, measured in Coulombs (C) Gaining or losing electrons produces a net charge, measured in Coulombs (C)

Electrical Forces Like charges repel, opposite charges attract. Like charges repel, opposite charges attract. Much stronger force than gravity. Much stronger force than gravity. Electrical forces form chemical bonds. Electrical forces form chemical bonds. +-

Electric Field All force is the same along a field line. All force is the same along a field line. Strength of field depends on amount of charge and distance between charges. Strength of field depends on amount of charge and distance between charges.

Static Electricity and Charging Charge can be transferred between objects by: Friction – rubbing removes electrons from one object Friction – rubbing removes electrons from one object Contact: touching charged object transfers charge Contact: touching charged object transfers charge Induction: Causing movement of charge by bringing a charged object close by. Induction: Causing movement of charge by bringing a charged object close by.

Conductors and Insulators Conductors, such as metals, allow electrons to move through the material easily. Conductors, such as metals, allow electrons to move through the material easily. Insulators do not allow electrons to move through the material easily, such as rubber. Insulators do not allow electrons to move through the material easily, such as rubber. Resistors slow the flow of electrical energy, changing it to other forms. Resistors slow the flow of electrical energy, changing it to other forms.

Electric Current Flow of Electric Charge Flow of Electric Charge Measured in Amperes (A) = coulombs/second Measured in Amperes (A) = coulombs/second A. Direct current (DC) = charge flows in one direction. (ex: battery) B. Alternating Current (AC) = Charge continuously reverses direction (in a home or school)

Resistance Resistance Resistance opposes the flow of electric current Resistance is Affected by: Thickness of wire – thin wires have more resistance. Thickness of wire – thin wires have more resistance. Length of Wire - longer wires have more resistance Length of Wire - longer wires have more resistance Temperature - Hot wires have more resistance. Temperature - Hot wires have more resistance.

OMG….20,000 Volts! Voltage is not the dangerous part of electricity. Voltage is not the dangerous part of electricity. Voltage is the potential to push electric charge. Think of it as potential energy. Voltage is the potential to push electric charge. Think of it as potential energy. 1.5 Volts – Low potential energy 120 Volts – Higher potential energy

Ohm’s Law (continued) Ohm’s Law is the mathematical formula between current, voltage, and resistance. Ohm’s Law is the mathematical formula between current, voltage, and resistance. Ohms Law is expressed by the formula: Ohms Law is expressed by the formula: V = IR V = IRWhere: V = Electric potential measured in Volts (V) I = Current measured in Amperes (A) R = Resistance measured in Ohms (Ω)

I got the POWER! Power is the measure at which work is performed (Work multiplied by time). Power is the measure at which work is performed (Work multiplied by time). Work changes on form of energy to another. Work changes on form of energy to another. Power is measured in Watts (W). Power is measured in Watts (W).

Electrical Power Formula P = IV Where: P = Power in Watts (W) I = Current in Amperes (A) V = Voltage in Volts (V)

Calculation Electrical Energy Electrical Energy is the rate at which Power is being used. Electrical Energy is the rate at which Power is being used. E = Pt Where: E = Electrical Energy in kilowatt hours (kWh) P = Power in kilowatts (kW) t = time in hours (h) Must use proper units! Power in Watts / 1000 = Power in kW