1. April 26/28 Physics

2. Table of Contents #. Date Title-Page – Page Number 29.April 14/15 Electrostatics 30.April 18/19 Electric Field 31.April 20/21 Electrostatics Problems 32.April 22/25 Circuits 33.April 26/28 Measuring Electricity 1

3. Homework #4

4. In: Label each diagram as series or parallel:

5. Objective: To understand Ohms law and measure: Simple Series Parallel circuits Success criteria: Calculate and measure current, voltage and resistance.

6. Amount of charge passing by every second: Current I=ΔQ Δt Measured in Amperes 1 Ampere= 1 Coulomb second

7. If a current of 45.0 mA exists in a metal wire, how much charge goes through in 20 minutes? How many electrons flow past a given cross section of the wire in 10.0 min? Sketch the direction of the current and the direction of the electrons motion.

8. Energy of each charge Electric potential V measured in Volts Energy charge

9. Voltage is like a pinball machine pushing the electrons out of the source into the circuit

10. Resistance to flow of electrons Resistance Measured in Ohms Ω

11. Resistance slows down the flow of electrons –Voltage used up –Light emitted –Heat emitted

12. How do you think the current would change if you increase the resistance in a circuit?

13. How do you think the current would change in a circuit if you increase the voltage into a circuit?

14. Ohms Law Georg Simon Ohm German physicist The relationship between current and voltage 1827

15. Ohms Law V=IR

16. A lightbulb has a resistance of 240 Ω when operating at a voltage of 120 V. What is the current in the bulb?

17. A toaster has a resistance of 10 kΩ. How much current flows through it at a voltage of 120V?

18. What is the resistance of a hair dryer if it runs at 120V with a current of 1 A?

19. What is the current of a lightning bolt that has a voltage of 10 million volts through air with a resistance of 2 KΩ?

20. Lab: Using a Multimeter Purpose: to measure circuits.

21. How to measure resistance voltage and current

24. Reading a Resistor

26. Measuring Voltage -Direct measurement of the push -Connect directly to the battery (or circuit if you want to measure change in voltage)

27. Measuring Resistance -Connect leads to resistor -Outside of a circuit

28. Measuring Current Must be a circuit Circuit must include the meter

29. Out: A hairdryer takes 1 amp of current at 120 V. What is its resistance?