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How can we make use of Ohm’s Law? Circuit Basics

What is a circuit? A continuous loop through which current flows from an area of high voltage to an area of low voltage.

Circuit Elements – Voltage Sources battery

Circuit Elements – Resistances fixed resistor variable resistor lamp

Circuit Elements – Switch

Circuit Elements – Measuring Devices Measures: VOLTAGE Connect to circuit: OUTSIDE Measures CURRENT Connect to circuit: INSIDE voltmeter ammeter

One Thing at a Time 4.2.4 Series Circuits

Definitions series circuit – a circuit in which two or more elements are connected end-to-end so that a single loop of current is formed.

Series Circuit Rules equivalent Resistance –> more resistors = more resistance Req = R1 + R2 + … current – same throughout circuit I = I1 = I2 = … voltage – voltages add up V = V1 + V2 + … All circuit components and the circuit as a whole must obey Ohm’s Law

V (V) I (A) R (Ω) R1 R2 R3 Total 2.5 0.5 5.0 4.0 0.5 8.0 1.0 0.5 2.0 5.0 Ω 8.0 Ω 2.0 Ω R1 R2 R3 7.5 V V (V) I (A) R (Ω) R1 R2 R3 Total 2.5 0.5 5.0 4.0 0.5 8.0 1.0 0.5 2.0 7.5 0.5 15

V (V) I (A) R (Ω) R1 R2 R3 Total 75 1.5 50 180 1.5 120 225 1.5 150 480 50 Ω 120 Ω 150 Ω R1 R2 R3 1.5A V (V) I (A) R (Ω) R1 R2 R3 Total 75 1.5 50 180 1.5 120 225 1.5 150 480 1.5 320