Download 11.1 current, potential difference and resistance

Name: ____________________ Date: ______________
11.1 CURRENT, POTENTIAL DIFFERENCE AND RESISTANCE
pg 432-447
YOU WILL BE TESTED ON KNOWING THE FOLLOWING:
VOCABULARY – Learn to define, use and understand the following terms
 resistance
 Very Important
 dry cell
 ohm
 battery
 Not as Important
 potential difference
 electrolyte
 voltage
 electrode
 voltmeter
 wet cell
 current
 fuel cell
 direct current
 alternating current

Know the differences between types of cells and batteries.
o A wet cell uses a liquid electrolyte. ie. car battery
o A dry cell uses a paste for an electrolyte. ie. D cell battery
o A fuel cell doesn’t use metals for their electrodes. Instead it uses a chemical reaction that is
quickly used up in a chemical reaction. ie. hydrogen cell.
o A battery is a series of cells all contained as a single unit. ie. 9V battery

Know what potential difference, current and resistance are.
o Potential difference is the difference in the amount of energy electricity has before and after an
area in a circuit. It is measured in volts (V).
o Current is the amount of electric charge a circuit has traveling through it. It is measured in
amperes (A).
o Resistance is the amount that the materials in circuit oppose (try to slow down) the current in a
circuit. It is measured in ohms ().
o Know the difference between AC and DC.
o Know how to use an ammeter, voltmeter and ohmmeter.
o What colour (red, black) leads to attach to each terminal (positive, negative)
CURRENT ELECTRICITY
1. Why isn’t static electricity useful for operating electrical devices?
2. How do you want electrons to flow when you operate an electrical device?
3. What are the two things that this section says you need for a circuit?
4. What is current electricity?
ELECTRIC CIRCUITS
5. What is an electrical load?
6. What does an electrical load do to electrical energy?
7. List the four things you need to make an electrical circuit. I have scrambled the letters of each one
to help you remember them. (reengy reoucs, ploceemt thap, chwist, alod)
Name: ____________________ Date: ______________
8. What is an open switch?
9. What is a closed switch?
ELECTROCHEMICAL CELLS
10. What is an electrochemical cell?
11. What is a battery?
12. What is the difference between an electrochemical cell and a battery?
13. Note: Usually an “electrochemical cell” is simply called a “cell”.
14. A cell is made of two different electrodes. What happens at each of the electrodes?
15. What does the electrolyte do in a cell?
WET CELLS AND DRY CELLS
16. What is the difference between a wet cell and a dry cell?
17. Where do you commonly find wet cells?
18. Where do you commonly find dry cells?
RECYCLING AND RECHARGING DRY CELLS
19. What do dry cells (common batteries) commonly have in them that makes them bad for the
environment to simply throw away?
20. Write down the following locations where it is convenient for Westdale students to drop off used
batteries:


Hotz Environmental Services, 239 Lottridge Street, Hamilton, Monday – Tuesday and
Thursday - Saturday 9 am – 3 pm, Wednesday 9 am – 8 pm.
Dundas Avenue Community Recycling Centres, 8 am - 6 pm, Monday to Saturday.
FUEL CELLS
21. What makes a fuel cell more reusable than reusable batteries?
POTENTIAL DIFFERENCE
22. What has more potential energy, an apple on a tree or an apple that has fallen from a tree?
23. What is another term for potential difference?
24. Explain what is meant by the term potential difference? (this is very important to understand)
25. What is potential difference measured in (what units is it measured in)?
26. What is the name of the equipment that you measure potential difference with?
HOW ELECTRONS TRANSFER ENERGY IN A CIRCUIT
27. When you turn on a circuit, do all the electrons along the wire move towards the negative terminal or
do the electrons all have to start from the negative terminal?
CURRENT
28. What is electric current?
29. What is the difference between direct current and alternating current?
30. What is a common source of DC?
31. What is a common source of AC?
Name: ____________________ Date: ______________
MEASURING CURRENT
32. What is the name of the equipment that you measure current with?
33. What is the unit current is measured in?
CURRENT ELECTRICITY AND STATIC ELECTRICITY
34. What is the difference between current and static electricity in relation to current?
ELECTRON FLOW AND CONVENTIONAL CURRENT
35. What colour is the positive terminal of an ammeter?
36. What colour is the negative terminal of an ammeter?
37. What terminal do you connect the red terminal of an ammeter to when measuring current in a
circuit?
38. Copy the following two sentences in quotes into your notebook. It will make more sense later on.
“Attach ammeters in series. Attach voltmeters in parallel.”
RESISTANCE
39. What is resistance?
40. What type of substance has more resistance, a conductor or an insulator?
41. What unit is resistance measured in?
42. What does resistance do to the energy in electricity, use it up or push it backwards?
RESISTANCE IN A CIRCUIT
43. What is a resistor?
44. Why does the filament in a light bulb produce light?
RESISTORS AND POTENTIAL DIFFERENCE
45. When does a circuit have a higher potential difference, before it enters a resistor or
after it enters a resistor?
46. What happens to a circuit’s potential energy when the electrons leave a resistor?
TYPES OF RESISTORS
47. List some of the materials that resistors are made out of?
RESISTANCE IN A WIRE
48. What would have less resistance, a thick wire or a thin wire?
CHECK AND REFLECT
pg 447
Answer the following questions.
Key Concept Review
1-10 (they are all important)
Connect Your Understanding
11, 13