Transcript OHMS LAW
Ohm’s Law explains the relationship between voltage (V ), current (I) and resistance (R) Used by electricians, automotive technicians, stereo installers It is the push or pressure behind the current flowing through a circuit. Measured in (V) volts. How you should be thinking about electric circuits: Voltage: a force that pushes the current through the circuit (water pump pushing water through hose) Current refers to the quantity (amount) of electrical flow. Measured in Amps (A) How you should be thinking about electric circuits: Current: the actual “substance” that is flowing through the wires of the circuit (electrons!) (like the water in the river) Resistance to the flow of the current. Measured in Ohms How you should be thinking about electric circuits: Resistance: friction that impedes the flow of current through the circuit (rocks in the river) 1. Assuming the resistance does not change: As voltage increases, current increases. As voltage decreases, current decreases. 2. Assuming the voltage does not change: As resistance increases, current decreases. As resistance decreases, current increases. Let's see how this works V = IxR I=V/R R=V/I Battery voltage is 12V Resistance 2 Ohm What is the Current? Given: V = 12 V R = 2Ω Unknown: I = ? Formula: I = V / R Solve: I = 12V / 2Ω Solution: 6 A (6 amps) Voltage is 12V Current is 4 Amps What is the Resistance? Given: V = 12V I = 4 A Unknown: R = ? Equation: R = V / I Solve: R = 12V / 4A Solution: R = 3Ω Multi meters/ DVOM Why do we need resistors Slow down current or decrease the voltage levels in a circuit. Creates a voltage drop that pushes current Prevents damage Used to produce heat and/or light What is Voltage? What is Current? What is Resistance? Series circuit : One pathway for current to flow. Example: Old Christmas lights More then one path way for current to flow. Used in most electrical vehicle circuits. Let’s watch a video about electricity to review all that we have learned.