Ch22.1 – Current Electricity. To get a current (a flow of charged particles), need to create a potential difference and sustain it. - batteries, generators.

Ch22.1 – Current Electricity

To get a current (a flow of charged particles), need to create a potential difference and sustain it. - batteries, generators Battery - place any 2 different materials in contact, electrons flow

Electronic series for several metals Ex1: what is the potential difference between: 1) Gold and copper? 2)Silver and lithium? 3) Iron and potassium? 4) Zinc and copper? 5) Copper and nickel Lithium Potassium Sodium Aluminum Zinc Iron Nickel Tin Lead Hydrogen Copper Mercury Silver Platinum Gold -3.0V -2.9V -2.7V -1.7V -.76V -.44V -.26V -.14V -.13V 0V.34V.8V 1.2V 1.3V

Electronic series for several metals Ex1: what is the potential difference between: 1) Gold and copper? 2)Silver and lithium? 3) Iron and potassium? 4) Zinc and copper? 5) Copper and nickel (1.3V) – (.34V) =.96V (.8V) – (-3.0V) = 3.8V (-.44V) –(-2.9V) = 2.46V (.34V) – (-.76V) = 1.10V (.34V) – (-.26V) =.6V Lithium Potassium Sodium Aluminum Zinc Iron Nickel Tin Lead Hydrogen Copper Mercury Silver Platinum Gold -3.0V -2.9V -2.7V -1.7V -.76V -.44V -.26V -.14V -.13V 0V.34V.8V 1.2V 1.3V

Current (I) - rate at which charge flows Amps = Coulombs sec I = q t Ex2: The belt on the Van de Graaf generator carries 20µC of charge to the sphere when it rotates in 2 seconds. Determine the current. Ex3: The starter motor in a car draws 180A of current from the battery in about 2 seconds. How much charge is flowing thru the circuit?

Black Brown Red Orange Yellow Green Blue Violet Gray White Gold Silver 0 1 2 3 4 5 6 7 8 9 +/- 5% +/- 10% Color Code Ex4) What is the resistance of: Red, green, blue, gold Ex5) brown, black brown, gold Ex6) Color stripes for 4000Ω +/-10% Ch22 HW #1 Resistance (R) – resists the flow of current. Symbol: - usually made of semi conductive materials, like carbon - resistors are small usually, so use a color code to ID

Resistance (R) – resists the flow of current. Symbol: - usually made of semi conductive materials, like carbon - resistors are small usually, so use a color code to ID Black Brown Red Orange Yellow Green Blue Violet Gray White Gold Silver 0 1 2 3 4 5 6 7 8 9 +/- 5% +/- 10% Color Code Ex4) What is the resistance of: Red, green, blue, gold 25 x 10 6 Ω +/-5% Ex5) brown, black brown, gold 10 x 10 1 Ω +/-10% Ex6) Color stripes for 4000Ω +/-10% Yellow, black, red, silver Ch22 HW #1

Lab22.1 Batteries - Lab due tomorrow - Ch22 HW#1 due at beginning of period

Ch22 HW#1 1 – 10 1. What is the potential for a wet cell battery made with nickel and zinc? 2. What is the potential for a wet cell battery made with Al and mercury? 3. What is the potential for a wet cell battery made with Pt and Cu? 4. What is the potential for a wet cell battery made with sodium and tin?

Ch22 HW#1 1 – 10 1. What is the potential for a wet cell battery made with nickel and zinc? -.76 – (-.26) =.5V 2. What is the potential for a wet cell battery made with Al and mercury? -1.7 – (.80) = 2.5V 3. What is the potential for a wet cell battery made with Pt and Cu? 4. What is the potential for a wet cell battery made with sodium and tin?

Ch22 HW#1 1 – 10 1. What is the potential for a wet cell battery made with nickel and zinc? -.76 – (-.26) =.5V 2. What is the potential for a wet cell battery made with Al and mercury? -1.7 – (.80) = 2.5V 3. What is the potential for a wet cell battery made with Pt and Cu?.34 – (1.2) =.86V 4. What is the potential for a wet cell battery made with sodium and tin? -.14 – (-2.7) = 2.56V

5. What is the current when 25 C of charge pass by a point in 10 seconds? 6. What is the current when 4.5  C pass by a point in 3.2 seconds? 7. What is the resistor with the colors: gray, green, red, silver? 8. What is the resistor with the colors: red, green, brown, gold? 9. Write the color band for a 1000 , +/- 5% resistor. 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? 7. What is the resistor with the colors: gray, green, red, silver? 8. What is the resistor with the colors: red, green, brown, gold? 9. Write the color band for a 1000 , +/- 5% resistor. 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? I = q/t = 4.5x10 -6 C/3.2s = 1.4x10 -6 A 7. What is the resistor with the colors: gray, green, red, silver? 8. What is the resistor with the colors: red, green, brown, gold? 9. Write the color band for a 1000 , +/- 5% resistor. 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? I = q/t = 4.5x10 -6 C/3.2s = 1.4x10 -6 A 7. What is the resistor with the colors: gray, green, red, silver? 85x10 2 Ω ± 10% 8. What is the resistor with the colors: red, green, brown, gold? 9. Write the color band for a 1000 , +/- 5% resistor. 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? I = q/t = 4.5x10 -6 C/3.2s = 1.4x10 -6 A 7. What is the resistor with the colors: gray, green, red, silver? 85x10 2 Ω ± 10% 8. What is the resistor with the colors: red, green, brown, gold? 25 x 10 1 Ω ± 5% 9. Write the color band for a 1000 , +/- 5% resistor. 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? I = q/t = 4.5x10 -6 C/3.2s = 1.4x10 -6 A 7. What is the resistor with the colors: gray, green, red, silver? 85x10 2 Ω ± 10% 8. What is the resistor with the colors: red, green, brown, gold? 25 x 10 1 Ω ± 5% 9. Write the color band for a 1000 , +/- 5% resistor. brown, black, red, gold 10. Write the color band for a 300,000 , +/-10% resistor.

5. What is the current when 25 C of charge pass by a point in 10 seconds? I = q/t = 25C/10s = 2.5A 6. What is the current when 4.5  C pass by a point in 3.2 seconds? I = q/t = 4.5x10 -6 C/3.2s = 1.4x10 -6 A 7. What is the resistor with the colors: gray, green, red, silver? 85x10 2 Ω ± 10% 8. What is the resistor with the colors: red, green, brown, gold? 25 x 10 1 Ω ± 5% 9. Write the color band for a 1000 , +/- 5% resistor. brown, black, red, gold 10. Write the color band for a 300,000 , +/-10% resistor. orange, black, yellow, silver

Ch22.1Equivalent resistance When resistors are in series (one attached to next, etc), just add them up. R eq = R 1 + R 2 +… Ex1) What is the equivalent resistance? 2Ω 3Ω 1Ω 2Ω 3Ω 4Ω 4Ω 4Ω 4Ω

Ch22.1Equivalent resistance When resistors are in series (one attached to next, etc), just add them up. R eq = R 1 + R 2 +… Ex1) What is the equivalent resistance? 2Ω 3Ω 1Ω 2Ω 3Ω 4Ω 4Ω 4Ω 4Ω = 5Ω = 6Ω = 16Ω

When resisters are in parallel (on different branches), use formula: Ex2) Find R eq : 2Ω2Ω2Ω2Ω 3Ω4Ω3Ω4Ω 5Ω5Ω5Ω5Ω5Ω5Ω

Complicated resistors: Ex3) Find R eq : 1Ω1Ω1Ω1Ω 1Ω1Ω = 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω1Ω1Ω 1Ω1Ω =

Complicated resistors: Ex3) Find R eq : 1Ω1Ω1Ω1Ω 1Ω1Ω = 1Ω.5Ω=1.5Ω 1Ω.86Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω1Ω1Ω 1Ω1Ω 1Ω1Ω 2Ω2Ω 1Ω1Ω.5Ω 1.5Ω 2Ω 1Ω1Ω 1.86Ω = = =

Ohm’s Law - voltage, current, & resistance are related by: V= I. R Ex4) A 12V battery is attached to 100Ω resistor. What current passes through the circuit? Ex5) A 20V battery pushes 2A thru a circuit. What kind of resistance does it feel? 100Ω12V I = 2A 20V ? Ch22 HW#2 11-20

Ch22 HW#2 11 – 20 For 11 – 14, what is the equivalent resistance of: 11. Two 10  resistors in series. 10  10  12. Two 10  resistors in parallel. 10  10  13. A 10 , 25 , and a 35  resistor in series. 10  25  35  14. A 300  and a 150  resistor in parallel. 300  150 

Ch22 HW#2 11 – 20 For 11 – 14, what is the equivalent resistance of: 11. Two 10  resistors in series. 10  10  = 20  12. Two 10  resistors in parallel. 10  = 5  10  13. A 10 , 25 , and a 35  resistor in series. 10  25  35  14. A 300  and a 150  resistor in parallel. 300  150 

Ch22 HW#2 11 – 20 For 11 – 14, what is the equivalent resistance of: 11. Two 10  resistors in series. 10  10  = 20  12. Two 10  resistors in parallel. 10  = 5  10  13. A 10 , 25 , and a 35  resistor in series. 10  25  35  = 70  14. A 300  and a 150  resistor in parallel. 300  = 100  150 

What is the equivalent resistance of: 15. 5  10  12  = 16. 12  = 6  17. 20  20  = 20 

What is the equivalent resistance of: 15. 5  10  12  = 27  16. 12  = 4  6  17. 20  20  = 20 

What is the equivalent resistance of: 15. 5  10  12  = 27  16. 12  = 4  6  17. 20  20  = 5  20 

18. A 9 V battery feels a resistance of 18  in the circuit it is attached to. How much current will it produce? 19. A 1.5 V D-Cell battery produces 0.75 A when in a circuit. How much resistance is in this circuit? 20. A 100  resistor has 1.1 A passing through it. What kind of voltage might cause this? 18Ω9V I =.75A 1.5V ? I=1.1A V=? R=100 

18. A 9 V battery feels a resistance of 18  in the circuit it is attached to. How much current will it produce? 19. A 1.5 V D-Cell battery produces 0.75 A when in a circuit. How much resistance is in this circuit? 20. A 100  resistor has 1.1 A passing through it. What kind of voltage might cause this? V = I. R = (1.1A)(100Ω) = 110V 18Ω9V I =.75A 1.5V ? I=1.1A V=? R=100 

2Ω2Ω2Ω2Ω 2Ω2Ω2Ω2Ω 2Ω 2Ω 2Ω 2Ω2Ω Ch22.1 cont. 1) =

Ex2) 4Ω 4Ω 8Ω 8Ω8Ω 8Ω8Ω 5Ω5Ω 10Ω

Current - in a series circuit, current stays the same through out circuit. - in a parallel circuit, current splits up to the branches. A 1) 5Ω5Ω 4Ω4Ω Ex3) How much does each ammeter read? 3V

Current - in a series circuit, current stays the same through out circuit. - in a parallel circuit, current splits up to the branches. A 1) 5Ω5Ω 4Ω4Ω R eq : 5+4 = 9 V 3V R eq 9Ω I == =.33A Ex3) How much does each ammeter read? 3V

A 15Ω10Ω 2) 18V

A 15Ω10Ω 2) V 50V R eq 6Ω I = == 8.3A 18V

3) 2Ω 10V 12Ω 6Ω A

4) 12V 4Ω 4Ω A A1A1 A2A2

5) 18V 3Ω 6Ω Ch22 HW#3 21 – 27 A A1A1 A2A2

21. 22. 23. 6Ω6Ω 6Ω6Ω 2Ω2Ω 8Ω8Ω 12Ω 8Ω8Ω 3Ω3Ω 2Ω2Ω 2Ω2Ω 3Ω3Ω

Ch22 HW#3 21 – 27 21. = 5Ω 22. 23. 6Ω6Ω 6Ω6Ω 2Ω2Ω 8Ω8Ω 12Ω 8Ω8Ω 3Ω3Ω 2Ω2Ω 2Ω2Ω 3Ω3Ω

Ch22 HW#3 21 – 27 21. = 5Ω 22. = 9.6Ω (4.8Ω) (4.8Ω) 23. 6Ω6Ω 6Ω6Ω 2Ω2Ω 8Ω8Ω 12Ω 8Ω8Ω 3Ω3Ω 2Ω2Ω 2Ω2Ω 3Ω3Ω

Ch22 HW#3 21 – 27 21. = 5Ω 22. = 9.6Ω (4.8Ω) (4.8Ω) 23. = 2.5Ω 6Ω6Ω 6Ω6Ω 2Ω2Ω 8Ω8Ω 12Ω 8Ω8Ω 3Ω3Ω 2Ω2Ω 2Ω2Ω 3Ω3Ω

24. 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω

= 8Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω 1Ω1Ω

25. What does the ammeter read? 26. What does the ammeter read? A 5Ω5Ω 12V A 3Ω3Ω 2Ω2Ω 10V

27. What does the ammeter read? A 4Ω4Ω 12V 2Ω2Ω 4Ω4Ω

Ch22.4 – Energy and Power Power is the rate that energy is used.Units: Ex1) A 6.0V battery delivers 0.50A to an electric motor. What power does it consume?

Electric Energy - measured in Joules or kilowatt-hours - conversion: 1kW. hr = 3.6x10 6 J

Ex2) A heater has a resistance of 10Ω, and operates at 120V. a) What is the current? b) What thermal energy is supplied by the heater in 10s? Ex3) A TV draws 5.0A when operated at 120V. a) How much power does it use? b) If the set operates for 5hrs per day for 30 days, how much energy does it use? c) At $0.50 per kW-hr, what does it cost?

For your lab tomorrow: Heat energy warms the water: Q = m. C p. ΔT A circuit supplies the electrical energy: E = I. V. t Conservation of energy: I. V. t = m. C p. ΔTchange in temp of H 2 O Voltmeter clockmass specific (5 min)of H 2 O heat Ch22 HW#4 28 – 33

Lab22.2 – Electric Heat - lab due tomorrow - Ch22 HW#4 due at beginning of period

Ch22 HW#4 28 – 33 28. A 12 V battery is supplying 180 A of current to a starter motor. How much power is it dissipating? 29. A 100  resistor has 2 A flowing through it. How much power is it dissipating? 30. The Hoover Dam produces 22,000 V at 50 A. What power is it producing?

31. The electrical wires between Hoover Dam and Victorville have a total of 100  of resistance. (That’s pretty small for so many miles of wire!) If the Hoover Dam energy produced were sent at 50 A, how much power would be dissipated by the time the energy reached us?!? 32. A heater has a resistance of 25  and operates at 110 V. What amount of electrical energy is converted to thermal energy in 1 minute? 33. A TI-89 calc draws 0.1 A when powered by its four AAA batteries. (That’s 6 V folks!) How much energy does it consume in 5 minutes?

Ch23.1 – Simple Series and Parallel Circuits Series - same current throughout circuit A 45V 47Ω 82Ω Ex 1) a 47Ω and 82Ω resistors are connected in series to a 45.0V battery. a) What does the ammeter read? b) What do the voltmeters read? V2V2 V1V1

Ch23.1 – Simple Series and Parallel Circuits Series - same current throughout circuit A 45V 47Ω 82Ω Ex 1) a 47Ω and 82Ω resistors are connected in series to a 45.0V battery. a) What does the ammeter read? b) What do the voltmeters read? R eq = 47 + 82 = 129Ω a) V 45V R eq 129Ω I = ==.35A b) V dropR1 = I ∙ R 1 = (.35)(47)= 16.4V V dropR2 = I ∙ R 2 = (.35)(82)= 28.6V V2V2 V1V1

Ex 2) A 9V battery is attached to a 400Ω and 500Ω resistors in series. What is the voltage drop across the 500Ω resistor? 9V 400Ω 500Ω

Ex 2) A 9V battery is attached to a 400Ω and 500Ω resistors in series. What is the voltage drop across the 500Ω resistor? 9V a) R eq1 = 900Ω b) V 9V R eq 900Ω I = ==.01A c) V dropR2 = I ∙ R 2 = (.01)(500)= 5V 400Ω 500Ω

Parallel – current from battery splits between branches Ex3) A 6 volt battery is attached to 2Ω and 9Ω resistors in parallel. What is the current produced by the battery? What is the current thru each resistor? 9Ω9Ω2Ω2Ω 6V

Parallel – current from battery splits between branches Ex3) A 6 volt battery is attached to 2Ω and 9Ω resistors in parallel. What is the current produced by the battery? What is the current thru each resistor? 9Ω9Ω2Ω2Ω 6V b) V dropR1 = 6V V dropR2 = 6V R eq = 1.6Ω V 6V R eq 2Ω I = == 3.7A a) I 1 = = = 3A V dropR1 6V R 1 2Ω I 2 = = =.7A V dropR2 6V R 2 9Ω

Ex4) 60Ω, 20Ω and 30Ω resistors connected in parallel to a 90V battery. a)Find R eq : b)Find current thru battery: c)Find current thru resistors: 60Ω 90V 20Ω30Ω Ch 23 HW#1 1-5

Ex4) 60Ω, 20Ω and 30Ω resistors connected in parallel to a 90V battery. a)Find R eq : b)Find current thru battery: c)Find current thru resistors: 60Ω 90V 20Ω30Ω a) b) V 90V R eq 10Ω I = == 9A R eq = 10Ω c) I 1 = = = 1.5A V dropR1 90V R 1 60Ω I 2 = = = 4.5A V dropR2 90V R 2 20Ω I 3 = = = 3A V dropR3 90V R 3 30Ω Ch 23 HW#1 1-5

Ch23 HW#1 1 – 5 1. Three 2  resistors are connected in series to a 12 V battery. What is current in the circuit? What is the voltage drop across each resistor? 2. A 10  and a 5  resistor are connected in series to a 30 V battery. What is the current in the circuit? What is the voltage drop across each resistor? 2Ω2Ω 2Ω2Ω 12V 10Ω 5Ω5Ω 30V 2Ω2Ω

3. A 100  resistor, a 75  resistor, and a 125  resistor are connected in series to a 110 V power supply. What is the current in the circuit? What is the voltage drop across each resistor? 4. A 25  and a 35  resistor are connected in parallel to a 12 V battery. What is the voltage drop across each resistor? What is the current through each resistor? What is the current through the battery? 100Ω 75Ω 110V 125Ω 25Ω 12V 35Ω

3. A 100  resistor, a 75  resistor, and a 125  resistor are connected in series to a 110 V power supply. What is the current in the circuit? What is the voltage drop across each resistor? 4. A 25  and a 35  resistor are connected in parallel to a 12V battery. What is the voltage drop across each resistor? What is the current through each resistor? What is the current through the battery? V drop = 12V 100Ω 75Ω 110V 125Ω 25Ω 12V 35Ω

5. A 100  resistor, a 75  resistor, and a 125  resistor are connected in parallel to a 110 V power supply. What is the voltage drop across the 75  resistor? What is the current through the each resistor? What is the current through the battery? 100Ω 110V 75Ω125Ω

5. A 100  resistor, a 75  resistor, and a 125  resistor are connected in parallel to a 110 V power supply. What is the voltage drop across the 75  resistor? What is the current through the each resistor? What is the current through the battery? V drop = 110V 100Ω 110V 75Ω125Ω

Ch23.3 – Applications I = ___A I = ___A I = ___A Short Circuit – circuit with very little resistance creates a very large current. Circuit breaker – automatic switch that opens when the current gets too high. GFI (Ground Fault Interrupter) – wall outlet that acts like a mini circuit breaker. (Bathrooms, kitchens, garages) 6Ω6Ω12V3Ω3Ω 0Ω0Ω

Ammeter – device that measures current. Connect in line (series). Must have low resistance so that it doesn’t affect the circuit. Voltmeter – device that measures voltage. Connect across (parallel). Must have high resistance so that barely any of the current branches to that part of the circuit. RV RV

Ex1) What does each voltmeter and each ammeter read? A2A2 10Ω 24V 5Ω5Ω 10Ω V A1A1

Ex2) What does each voltmeter and each ammeter read? Ch23 HW#2 6 – 9 A2A2 10Ω 45V 15Ω 7Ω7Ω V A1A1

Ch23 HW#2 6 – 9 6. A1A1 10Ω A2A2 A3A3 10V

7. A3A3 3Ω3Ω 12V 6Ω6Ω A1A1 A2A2

8. A4A4 3Ω3Ω 120V A1A1 5Ω5Ω A2A2 7Ω7Ω A3A3

9. A1A1 9Ω9Ω 9Ω9Ω A2A2 A3A3 9V 4.5Ω

Ch22,23 Rev 1 – 10 1. What is the potential for a wet cell battery made with platinum and copper? 2. Color band for 1000Ω +/-5% resistor? R eq for: 2Ω2Ω 2Ω2Ω 2Ω2Ω 2Ω2Ω 2Ω2Ω 2Ω2Ω 2Ω2Ω 2Ω2Ω2Ω2Ω 2Ω2Ω

4. 12V battery with 150Ω of resistance. How much current? 5. 2 D-cells have a potential of 3.0V, produce 0.90A in a circuit. How much resistance? 6. 100Ω 50V 1000Ω A

7. 110V power supply operates at 25A to run a compressor. How much power is it dissipating? 8. A 135Ω resistor has 3.5A flowing thru it. How much power? 9. Heater with a resistance of 40Ω operates at 110V. How much electrical energy does it convert to thermal energy in 10min? 10. A watch draws 0.005A when powered by its 3.1V battery. How much energy does it consume in 1 day?

11. a. R eq for parallel: b. R eq for total: c. I for circuit: d. V drops : e. I’s for branches: f. Power from battery: g. Power dissipated by R 1. 4Ω4Ω 4Ω4Ω A 12V R 1 =4Ω V

Ch22.1 – Current Electricity. To get a current (a flow of charged particles), need to create a potential difference and sustain it. - batteries, generators.

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Ch22.1 – Current Electricity. To get a current (a flow of charged particles), need to create a potential difference and sustain it. - batteries, generators.

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Presentation on theme: "Ch22.1 – Current Electricity. To get a current (a flow of charged particles), need to create a potential difference and sustain it. - batteries, generators."— Presentation transcript:

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