# Electricity & Magnetism

## Physical Science - Middle School

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+ + ALKALINE BA TTER Y + + A Series Circuit A Parallel Circuit + + + 150 Watts 1,200 Watts Resistance (ohms) Voltage (volts) Current (amps) Voltage (volts) Power (watts) Current (amps) Electric Charge All matter is made up of atoms. Atoms are made of positively charged protons, negatively charged electrons and neutrons which carry no charge. Charged objects either push or pull on other charged objects. Objects with like charges repel each other, while objects with opposite charges attract each other. A flow of electric charges is called "electric cur rent." The rate of electric current, expressed in amps (A), measures the amount of charges that flow through a material past a given point per second. The letter I is used as the symbol for current in equations. There are two kinds of electric current Alternating Current (AC) and Direct Current (DC). The charges in Alternating Current (AC) flow one way, then the other way, continually reversing direction. The charges in Direct Current (DC) always flow in the same direction. Circuits Objects with the same charge repel each other Objects with opposite charges attract each other Direct Current Alternating Current The water has less resistance flowing through a wide pipe than a narrow one. wide narrow A wide wire has less resistance and allows greater current to flow through. Electric Current Voltage Voltage is the electrical force, or "pressure", that causes current to flow in a circuit. Voltage is measured in volts (V). Resistance Resistance is the opposition to the flow of electricity in a circuit. Resistance is measured in ohms (Ω). In equations, the symbol for resistance is the letter R. Ohm’s Law Ohm’s law, named after Mr. Georg Ohm, a mathematician and physicist (1789-1854) from Bavaria, defines the mathematical relationship between voltage, current and resistance. Electric Power Electric power is the rate at which electrical energy is converted into other forms of energy. Electric power is measured in units called watts (W). Series Circuits The current in a series circuit can only flow in one path. The current must flow through all the circuit components. In the series circuit below, the current flows through each of the bulbs in sequence. If any of the bulbs fail, the others will stop working as current cannot flow through the rest of the circuit. Parallel Circuits The current in a parallel circuit has at least two independent paths to flow. In the parallel circuit below, the current can flow through each of the bulbs without first having to flow through any others. If any of the bulbs fail, the others will still work as current can still flow through the rest of the circuit. © Copyright NewPath Learning. All Rights Reserved. 94-4807 www.newpathlearning.com Electricity
\|xiBAHBDy01800rzu + + A Series Circuit A Parallel Circuit Electric Charge All matter is made up of ___________________. Atoms are made of ___________________. charged protons, negatively charged ___________________, and ___________________, which carry no charge. Charged objects either push or pull on other charged objects. Objects with like charges ___________________ each other, while objects with opposite charges ___________________ each other. Electric Current A flow of electric charges is called "___________________ ___________________ . " The rate of electric current expressed in amps (A) measures the amount of ___________________ that flow through a material past a given point per second. The letter _____ is used as the symbol for current in equations. There are two kinds of electric current __________________ __________________ and ___________________ ___________________ . The charges in ___________________ ___________________ flow one way, then the other way, continually reversing direction. The charges in ___________________ ___________________ always flow in the same direction. Voltage What is voltage? ___________ _________________________ _________________________ _________________________ _________________________ Resistance What is resistance? _________ _________________________ _________________________ _________________________ _________________________ Ohm’s Law Describe Ohm’s Law: ___________ _____________________________ _____________________________ _____________________________ _____________________________ Electric Power What is electric power? __________ ______________________________ ______________________________ ______________________________ ______________________________ Electric power is measured in ______________________ . Circuits Series Circuits Describe a series circuit: _______________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ Parallel Circuits Describe a parallel circuit: _______________ __________________________________ _______________________________ _____________________________ ___________________________ ________________________ ___________________ __________________ © Copyright NewPath Learning. All Rights Reserved. 94-4807 www.newpathlearning.com Electricity Key Vocabulary Terms alternating current amp atom attract charge circuit direct current electric current electric power electricity matter ohm Ohm’s law parallel circuit repel resistance series circuit volt voltage watt Current (amps) Voltage (volts) Power (watts) Resistance (ohms) Voltage (volts) Current (amps)