1. Parallel Circuits Monday, April 6, 2015

2. Unit 9: Electricity Friday, 4/3 Pick up a warm-up sheet from the Physics bin and do the following: Write your name on top of the paper Complete the questions uses GUESS. You will have five minutes to complete. Upcoming dates: Tuesday, 4/7 – last day to turn in missing electricity assignments Wednesday, 4/8 – open note quiz (DATE CHANGE) Friday, 4/10 – Electricity test (grade will go on the 6SW) Friday, 4/10 – End of 5SW

3. Unit Overview Types of Electricity Dynamic Static Direct Current (DC) Alternating Current (AC) Series ComplexParallel

4. Circuit – In Series Only one path

5. Circuit – In Parallel More than one path

6. Directions Using the items in your box create a parallel circuit with three branches. Place a light bulb in each branch. When all three light bulbs have illuminated do the following: Disconnect a light bulb from one branch of the circuit. Record your observations. Disconnect two light bulbs from two branches. Record your observations.

7. What do you think? If a circuit has multiple branches will the voltage, resistance, and current behave differently? Write your thoughts in your notes.

9. Kirchhoff’s Rules Junction Rule: the sum of all currents entering the junction must equal the sum of all currents leaving the junction.

10. Parallel 1. reciprocal of the total resistance is the 1. reciprocal of the total resistance is the sum of the reciprocals of the separate sum of the reciprocals of the separate resistors resistors 1/R T = 1/R 1 + 1/R 2 +1/R 3 +... 2. total current is the sum of the current through each resistor through each resistor I T = I 1 + I 2 + I 3 +... 3. potential difference is the same across each resistor each resistor V T = V 1 = V 2 = V 3 =... In other words, in a parallel circuit, resistance adds as reciprocals, voltage stays the same, and current splits. In other words, in a parallel circuit, resistance adds as reciprocals, voltage stays the same, and current splits.

12. Practice

13. Review