CIRCUITS

• Light intensity is proportional to (electric) power
• Electric power represents the rate at which electrical energy is transferred or converted into other forms of energy (such as heat, light, or mechanical energy) within a circuit.
• Power is the rate of transferred(expending or absorbing) energy measured in watts, (W)
• Power is also the product of the potential difference or voltage across the particular element, multiplied by the current flowing through it.
• P = IV
• I = P/V
• V = P/I
• Electrical power is the product of the current and the \voltage.
• Electric power is the rate per unit time, at which electrical energy is transferred by an electric circuit.
• An electric circuit is a conducting loop In which current can transfer electrical energy from a suitable source to a useful load
• Series Circuits only have one path
• Parallel circuits have more than one path - branches
• more batteries in series = more current is available and bulbs become brighter
• when too many batteries are added, bulbs may fuse
• Ohm’s law states that the Current is directly proportional to thevoltage and inversely proportional to the resistance
• Resistance is measured in Ohms (Ω)
• the lower the resistance, the higher the current
• The greater the voltage, the higher the current
• Bulbs in parallel are brighter than bulbs in series
• A bulb connected to two cells in series is brighter than one connected to two cells in parallel.
• A voltmeter is placed in parallel with the voltage source to receive fullvoltage and must have a large resistance to limit its effect on the circuit.
• In an electric circuit, the potential difference across a resistor is equal to the product of the current passing through it and its resistance.
• An ammeter is placed in series with the component being tested to measure the current flowing through it. It has low resistance so that it does not affect the flow of electrons.
• • Electric energy consumed over a certain period of time — what we are paying to electric utility companies.
• E = Pt
• • Our body is a good conductor of electricity.
• • Electric shock happens when an electric current passes through the human body.
• • Arc flash happens when you have a very large, explosive discharge of electric energy in equipment.
• The current passing through a victim is usually determined by the skin resistance.
• The amount of current that passes through the body is the actual measure of shock intensity.
• A.C. is more dangerous than D.C.
• A ground fault circuit interrupter (GFCI) can help prevent electrocution. If a person’s body starts to receive a shock, the GFCI senses this and cuts off the power before he/she can get injured.
• Keep all electrical wires away from water sources.
• When using extension cords, make sure they are rated for outdoor use if used outside.
• When using electrical tools or appliances outside, make sure they are rated for outdoor use.
• If there are no outlets with GFCIs nearby, use extension cords with GFCIs on them.
• When working on circuits, turn off all switches and unplug appliances first.
• To avoid electrical hazards, always use ladders made of nonconducting materials such as wood or fiberglass.
• If an appliance has a three-pronged plug, do not remove the third prong or force it into a two-hole outlet.