Electricity PDF

Electricity The Nature of Matter All matter is made up of atoms, which are tiny particles consisting of charged particles: neutrons, protons, electrons. electrons = protons ○ negatively charged # electrons > # protons ○ negatively charged...

Electricity The Nature of Matter All matter is made up of atoms, which are tiny particles consisting of charged particles: neutrons, protons, electrons. electrons = protons ○ negatively charged # electrons > # protons ○ negatively charged # electrons < # protons ○ positively charged Static Electricity Form of electrical energy created by the buildup of stationary charges. Gather of charges often occurs on the surface of insulators. Friction creates static electricity; one substance loses electrons (becomes positive), and one gains (becomes negative). [Diagram]: Neutral: Equal protons/electrons. Negatively charged: Gains electrons (-2). Positively charged: Loses electrons (+3). Charged objects cause charge separation when they are brought close to neutral objects Electrical Discharge Built-up charges on objects are attracted to another object and "jump" to it. This is a "shock," and you may see a spark. Results in a discharge of the electrons in one of the objects to the other. Electrons are the ones that “jump” to the positively charged surface 3 Laws of Electric Charge 1. Opposite charges attract. 2. Like charges repel. 3. Charged objects discharge to neutral objects. When a charged object is brought near a neutral object, it causes the charges within the neutral object to separate. This creates an attraction between the opposite charges, pulling the neutral object towards the charged one. Lightning occurs when warm air floats above cool air, condensing and releasing energy. Warm air rises; electrons transfer to raindrops, creating charge in cloud: ○ Bottom = (-) ○ Top = (+) Lightning strikes when electrons from the cloud are attracted to the positively charged surface. A circuit is a complete path around which electric current can flow. They are composed of wires that connect cells to electrical devices in a way that allows electric current to flow continuously in a loop. Most circuits have switches. Complete circuit – An unbroken path along which electric current flows. Incomplete circuit – A circuit with an interruption in the flow of current. Cell – A single unit that can produce electric current. The steady flow of charged particles is called electrical current Ohm’s Law deals with the relationship between voltage and current in an ideal conductor Symbol Word Measured in… Unit of Measurement V Voltage volts V I Current amps A R Resistance ohms Ω Electriacl Power is the rate at which electrical eneery is converted into another form, such as motion, heat, or light Symbol Word Measured in… Unit of Measurement P power Watts (100 watts = W 1Kw) E energy joules J t time seconds s Power can ALSO be calculated using to following formula: Symbol Word Measured in… Unit of Measurement P power watts W I current amps A V voltage volts V Formulas: V = IR V = P/I R = V/I I = P/V I = V/R P = E/T E = PT T = E/P P = IV Efficiency = Energyout x 100% Energyin Efficiency = Useful Energy output x 100% Total Energy input Series Circuit There is only one pathway for the current. If the pathway is interrupted, the whole circuit cannot function Parallel Circuits have a separate current path for each section of the circuit