Circuit Basics & Series Circuits Aim: How are circuits designed and connected?

Circuit A simple circuit is mainly made of a voltage source, connecting wires, and a circuit element like a resistor or a lamp INDIVIDUAL parts & the ENTIRE circuit obey OHM’S Law

Circuit Parts NameSymbolDescription Cell A device that converts chemical energy to electrical energy. Long line = (+) Terminal BatteryA combination of two or more cells Switch A device for making/breaking/changing electrical connections Resistor A device designed to have a fixed resistance

Circuit Parts NameSymbolDescription Variable Resistor A device that can change its resistance LampA “resistor” that gives off light Voltmeter A device that measures voltage across a device. MUST BE CONNECTED OUTSIDE OF THE CIRCUIT Ammeter A device that measures current in a circuit. MUST BE CONNECTED INSIDE THE CIRCUIT

Making Connections V1V1 R1R1 VOLTMETERS are connected OUTSIDE of a circuit measuring the “voltage drop” of the circuit element AMMETERS are connected WITHIN the circuit itself to measure the amount of the current flow in that section

Making Connections V1V1 R1R1 R2R2

Series Circuit A circuit composing of at least two circuit elements connected end to end, creating a SINGLE LOOP V1V1 R1R1

Series Circuit Rules The CURRENT in a series circuit is CONSTANT at any and all points in the circuit The TOTAL VOLTAGE of the circuit is equal to the voltage drop at EACH resistor The TOTAL (Equivalent) RESISTANCE of the circuit is equal to the SUM of all resistors

Series Circuit Rules The entire circuit as a whole AND each individual part, mainly resistors, obey Ohm’s Law By convention, the current flow in a circuit move from the POSITIVE terminal of the battery to the NEGATIVE terminal of the battery

Example #1 Determine (a) the equivalent resistance, (b) the current, (c) the voltage drop at each resistor 20V 6Ω6Ω 10Ω

Example #2 Determine (a) the equivalent resistance, (b) resistance of R 1,(c) the voltage drop at each resistor 30V R1R1 10Ω 2A

Summary Describe the primary characteristic of a Series Circuit In a series circuit, describe the rules for… – Voltage – Resistance – Current