ohmslaw-work,power and energy.grade 8 science.pptx

work, power and energy

1. OHM’S LAW

2. Fundamental units of electricity Voltage is the pressure that pushes current to flow within a load through a conductor Current is the flow of electrons in a circuit Resistance is the opposition of the flow of electrons in a circuit. Power is the product of work done

3. OBJECTIVES Define Ohm’s Law; Solve problems using Ohm’s Law; Appreciate the use of Ohm’s law in measurement and calculation of electrical load; and Practice accuracy in computation.

4. What is Ohm’s Law? states that the current in the circuit is directly proportional to the voltage and inversely proportional to its resistance.

5. Where: I is the current through the conductor in units of amperes and the flow electrons in a circuit. V is the voltage measured across the conductor in units of volts and an electrical pressure that pushes current to flow within a load through a conductor. R is the resistance of the conductor in units of ohms (Ω) and the opposition of the flow of electrons in a circuit.

6. It also means that if the voltage increases the current also increases and if the voltage decreases the current will also decrease in which the resistance is constant . More specifically, Ohm's law states that the R in this relation is constant, independent of the current. The law was named after the German physicist Georg Ohm ,

7. How will you find the value of V, I, and R using Ohm’s law?

8. No. 1 - A light bulb is plugged into a wall outlet of 220 V with a resistance of 0.02 Ω. What is the current of the circuit? No. 2 - A voltage 6.0V is connected to a lamp and a current of 2.0 amperes flows. All the wires are resistance-free. What is the resistance of the lamp? No. 3 - Another flash light bulb is rated to use 0.3 amps and has a resistance of 4.0 Ω. How much voltage does this bulb use?

9. Assignment Study in advance about the “Parts of the Multi-tester”

10. Concluding Activity Each group will be given strips of paper containing word/s to complete the Ohm’s Law statement , and post it on the space where they think it suits best. Then, each group will choose a representative to give a brief explanation about their understanding on the topic.