Electrical Circuits

• Electricity is created by the flow of electrons and is a form of energy that can be transported from one place to another.
• Voltage: The amount of energy that can be provided to the electrons by a power source
• Current: The rate of flow of electrons
• Resistance: The difficulty of ‘flow’ in a circuit
• The 5 main components of a circuit include the: wires, load (bulb resistor, etc), switch, power source, voltmeter, ammeter.
• The essential elements in a basic electrical circuit consist of: A source, load, and ground
• Electricity cannot flow without a power source (battery), and a load (bulb or resistor-electrical device/ component) and a closed conductive path (wires connecting it).
• Ohm’s Law: a law that states that the current through a conductor between two points is directly proportional to the voltage across the two points
• Resistance (R): 1000 Ω
• Voltage applied (V): 200 V
• Current (I = V/R): 0.2 A
• Water pump analogy: valve: switch pump: power source (battery) water wheel: bulb water:electrons pipe:wires
• Series circuit
• All components are on the same electrical oath
• Components spilt the energy provide - each additional component works less effectively (light bulb becomes dimmer)
• A fault in any part of the circuit will cause the whole circuit to fail (christmas lights)
• Parallel circuit
• Components are on different electrical paths
• All components draw the same amount of energy - additional components continue to work at maxim efficiency
• If a single component fails, the rest of the circuit still works (used in households)
• Voltmeter: measures the voltage change across a component in a circuit
• Must be connected parallel to the component being measured
• Ammeter: measures the amount of current in a circuit
• Must connected in a series with the circuit
• A transistor is a small electronic device that can be used as a switch (can be turned on or off by current) or an amplifier (can boost current).
• PE + KE = TOTAL ENERGY
• According to the rule of conservation of energy, energy cannot be generated or destroyed; it can only be transformed from one type of energy to another
• This indicates that unless energy is introduced from outside, a system always has the same quantity of energy.
• We can save energy industrially by using: Energy Audits, Control and Manage Machinery Use, Using LED and Solar lighting., Optimizing Air Compressors.
• We can save energy domestically by using: Replace your light bulbs Install a programmable thermostat, Use energy efficient appliances, Reduce water heating expenses
• If society values it = more research funding
• Energy decisions are influenced by economic, environmental, social factors