2. Part II: Electrochemistry

3. Electricity is generated by the movement of charged particles, in which opposite charges ___________ one another and like charges _________ one another. a) repel, repel b) repel, attract c) attract, repel d) repel, repel

4. Electricity is generated by the movement of charged particles, in which opposite charges ___________ one another and like charges _________ one another. a) repel, repel b) repel, attract c) attract, repel d) repel, repel

5. Electric charge is measured in ________________ Electric current is measured in _______________ Electric resistance is measured in _____________ Electric potential difference is measured in ________. Electric power is measured in ________________

6. Electric charge is measured in Coulombs Electric current is measured in amperes Electric resistance is measured in ohms (Ω) Electric potential difference is measured in volts. Electric power is measured in watts

7. What is Ohm’s Law? Provide 1. The a mathematical equation in words, _________________________________ 2. The a mathematical equation in one letter symbols, _________________________________ 3. And the mathematical equation in units. _________________________________

8. What is Ohm’s Law? Provide 1. The a mathematical equation in words, Volts = Current X Resistance 2. The a mathematical equation in one letter symbols, V= IR 3. And the mathematical equation in units. volts = amperes X ohms

9. How is electric power calculated? Provide 1. The a mathematical equation in words, _________________________________ 2. The a mathematical equation in one letter symbols, _________________________________ 3. And the mathematical equation in units. _________________________________

10. How is electric power calculated? Provide 1. The a mathematical equation in words, Power = Current X Voltage 2. The a mathematical equation in one letter symbols, P= IV 3. And the mathematical equation in units. watts = amperes X volts

11. In a battery-powered circuit, because they have a _______ charge, electrons flow from the ______ to the ______. a) negative; anode; cathode b) negative; cathode; anode c) positive; anode; cathode d) positive; cathode ; anode

12. In a battery-powered circuit, because they have a _______ charge, electrons flow from the ______ to the ______. a) negative; anode; cathode b) negative; cathode; anode c) positive; anode; cathode d) positive; cathode ; anode

13. A circuit in which the path is complete, with no gaps is called a(n) _________________ because the _________ can flow. a) open circuit, current b) open wire, resistance c) closed circuit, current d) closed system, resistance

14. A circuit in which the path is complete, with no gaps is called a(n) _________________ because the _________ can flow. a) open circuit, current b) open wire, resistance c) closed circuit, current d) closed system, resistance

15. In a given circuit, increasing the length of the wire has which effect? a) Increases resistance b) Decreases resistance c) Increases current d) Has no affect on resistance or current e) B and C

16. In a given circuit, increasing the length of the wire has which effect? a) Increases resistance b) Decreases resistance c) Increases current d) Has no affect on resistance or current e) B and C Making the wire longer increases resistance, and therefore decreases current (OHM’S LAW!!!), thereby also decreasing the power (since P=IV!!!)

17. How much power is used by a 9-V battery that produces a 3 amp current?

18. How much power is used by a 9-V battery that produces a 3 amp current? Remember, P= IV ; or watts = amperes X volts. Thus, in this case, watts = 3 amperes X 9 Volts = 27 watts

19. A circuit in which the path has gaps is called a(n) _________________ and the current __________ flow. a) open wire, can b) open circuit, cannot c) closed circuit, can d) closed system, cannot

20. A circuit in which the path has gaps is called a(n) _________________ and the current __________ flow. a) open wire, can b) open circuit, cannot c) closed circuit, can d) closed system, cannot

21. You have two light bulbs, one with a rating of 50 watts and one with a rating of 100 watts. Remember that the voltage across each would be the same if they were placed in a light socket. How would the current through each light bulb compare? a) Both bulbs would draw the same current. b) The higher watt bulb would draw less current. c) The lower watt bulb would draw less current. d) The lower watt bulb would draw more current.

22. You have two light bulbs, one with a rating of 50 watts and one with a rating of 100 watts. Remember that the voltage across each would be the same if they were placed in a light socket. How would the current through each light bulb compare? a) Both bulbs would draw the same current. b) The higher watt bulb would draw more current. c) The higher watt bulb would draw less current. d) The lower watt bulb would draw more current. A higher watt bulb is drawing more power (remember watts is a measure of power..). And the power equation tells us that P = IV, which means that at a given voltage more power requires more current.

23. How much power is used when a 3 V battery produces 0.1 amp of current?

24. How much power is used when a 3 V battery produces 0.1 amp of current? Remember, P= IV ; or watts = amperes X volts. Thus, in this case, watts = 0.1 amperes X 3 volts, = 0.3 watts

25. Current is measured in _____, resistance in measured in _____ and power is measured in _____. a) watts, ohms, amperes b) amperes, ohms, watts c) Coulombs, volts, amperes d) ohms, amperes, watts e) amperes, ohms, Coulombs

26. Current is measured in _____, resistance in measured in _____ and power is measured in _____. a) watts, ohms, amperes b) amperes, ohms, watts c) Coulombs, volts, amperes d) ohms, amperes, watts e) amperes, ohms, Coulombs

27. In a given circuit, increasing the diameter of the wire (making it wider…) has which effect? a) Increases resistance b) Decreases resistance c) Increases current d) Has no affect on resistance or current e) B and C

28. In a given circuit, increasing the diameter of the wire (making it wider…) has which effect? a) Increases resistance b) Decreases resistance c) Increases current d) Has no affect on resistance or current e) B and C Making the wire wider decreases the resistance, and therefore increases the current (OHM’S LAW!!!), thereby also increasing the power (since P=IV!!!)

29. What is the resistance of a device if the current through it is 10 amps and the voltage across it is 5 volts?

30. Remember, V= IR ; or volts = amperes X ohms Therefore, R = V ; or ohms = volts. I amperes Thus, in this case, ohms = 5 volts = 0.5 ohms 10 amperes

31. Label the circuit below to show the following: anode, battery, cathode, direction of electron flow, resistor, and switch. LED light (0.40 Amp, 2.6 Volts)

32. Label the circuit below to show the following: anode, battery, cathode, direction of electron flow, resistor, and switch. LED light (0.40 Amp, 2.6 Volts) Battery Anode Cathode Electron flow Switch Resistor Electron flow

33. What power is used if a resistance of 100 ohms has a current of 0.1 amps flowing through it?

34. What power is used if a resistance of 100 ohms has a current of 0.1 amps flowing through it? Remember, P= IV ; or watts = amperes X volts Here we must first determine the volts before we can solve for watts. From Ohm’s Law, we know that V= IR ; or volts = amperes X ohms Thus, in this case, volts = 0.1 amps X 100 ohms = 10 volts. Substituting this value in our power equation above gives: watts = 0.1 amperes X 10 volts = 1 watt

35. What is the power used in a device if the resistance is 100 ohms and the voltage across it is 4V?

36. Remember, P= IV ; or watts = amperes X volts Here we must first determine the amperes before we can solve for watts. From Ohm’s Law, we know that V= IR ; or volts = amperes X ohms. Rearranging this equation gives: amperes = volts ohms Thus, in this case, amperes = 4 volts =.04 amperes 100 ohms Substituting this value in our power equation above gives: watts = 0.04 amperes X 4 volts =.16 watts