Measuring Electricity, Ohm's Law & Circuits - Multimeter, Series, Parallel & Kirchhoff's Laws

Why does a 470 Ω resistor read only 387 Ω on your multimeter? And why does plugging in one more appliance trip the breaker? In this video you'll learn how to measure electricity like an engineer and how current, voltage and resistance behave in real circuits: • How to use a multimeter: voltage (across), current (through, in series) and resistance (power off) • Why you should measure a resistor out of the circuit (470 Ω with 2.2 kΩ in parallel reads 387 Ω) • Ideal meters: a voltmeter in series is an open circuit, an ammeter in parallel is a short circuit • Ohm's Law: V = I × R, with the flashlight example (6 V / 150 Ω = 0.04 A = 40 mA) • Series circuits and Kirchhoff's Voltage Law (12 V, 1,890 Ω, 6.349 mA, drops of 1.397 V + 2.984 V + 7.619 V) • Parallel circuits and Kirchhoff's Current Law (15 V, total resistance 346.59 Ω, total current 43.278 mA) • Why more parallel paths mean less resistance and more current • Home circuits: lamp + toaster + microwave = 18 A, above the 15 A breaker limit • Combination circuits and electrical power (P = I × V) Perfect for Principles of Engineering (PLTW POE), physics and intro electronics students. More free STEM resources: https://stemeducation.tech Chapters: 0:00 Electricity All Around You 0:21 The Multimeter: Volts, Amps & Ohms 0:38 Measuring Voltage & Current 1:07 Measuring Resistance: 470 Ω Reads 387 Ω? 1:48 Wiring Mistakes: Voltmeter in Series, Ammeter in Parallel 2:26 Ohm's Law & the Ohm's Law Triangle 2:43 Flashlight Example: 6 V and 150 Ω 2:58 Series Circuits & Kirchhoff's Voltage Law 4:23 Parallel Circuits & Kirchhoff's Current Law 5:13 More Paths, Less Resistance 5:59 Home Circuits: Every Appliance Adds a Path 6:24 Electrical Power & the 15 A Breaker 7:38 Combination Circuits 7:56 Recap: Voltmeter & Ammeter Rules 8:11 Thanks for Watching