Presentation on theme: "Ohm’s Law The most important fundamental law in electronics is Ohm’s law, which relates voltage, current, and resistance. Georg Simon Ohm (1787-1854) studied."— Presentation transcript:
1 Ohm’s LawThe most important fundamental law in electronics is Ohm’s law, which relates voltage, current, and resistance.Georg Simon Ohm ( ) studied the relationship between voltage, current, and resistance and formulated the equation that bears his name.
2 Summary Review of V, I, and R Voltage is the amount of energy per charge available tomove electrons from one point to another in a circuit.the rate of charge flow and is measured inamperes.Current isthe opposition to current and is measuredin ohms.Resistance isSI unit for voltage is volts (v)SI unit for current is amps (A)SI unit for resistance is ohms (Ω)
3 Question: Question: Question: If you need to solve for current, Ohm’s law is:Question:What is the current in from a 12 V source if the resistance is 10 W?1.2 AIf you need to solve for voltage, Ohm’s law is:Question:What is the voltage across a 680 W resistor if the current is 0.25 A?170 VIf you need to solve for resistance, Ohm’s law is:115 VWhat is the resistance of the bulb?Question:132 W
4 PracticeWhat value of resistor would be used to permit a current of 0.2 A to flow using a 6V supply?Calculate the voltage across a 300 ohm resistor when a current of A flows through it.A resistor allows a current of 0.6 A to flow when connected to a 9.6 volt supply. What current would flow if the same resistor was connected to a 12.8 V supply?R=V/IR=6/0.2R=30ΩV=IRV=(0.004)(300)V=1.2VR=V/II=V/RR=9.6/0.6R=16ΩI=12.8/16I=0.8 A