SNC 1DName: ______

Dynamic Electricity ReviewDate: ______

1. Choose from the appropriate boxes below to fill in the table which follows.

Symbol Box / Description Box / Unit Box
I
R
V / a) Measures the energy that each group of electrons carry around in the circuit.
b) Measures the amount that a load in the circuit will slow down the flow of electrons.
c) Measures the number of electrons passing by a point in a circuit per second. / Ohm,
Volt, V
Ampere, A
Quantity / Symbol / Description / Unit
Current
Potential Difference or Voltage
Resistance

2. Draw circuit diagrams for the following two circuits:.

a) one dry cell, one closed switch, two light bulbs wired in series, one ammeter measuring the current coming out of the dry cell, one voltmeter measuring the potential difference across the first light bulb in the circuit

b) two dry cells, one open switch, two light bulbs wired in parallel, one ammeter measuring the current coming out of one bulb, one voltmeter measuring the potential difference across the dry cells

2. There are two light bulbs shown in each of the following circuits.

A.

Schematic Diagram: / B.

______
Schematic Diagram:

a) On the blankprovided underneath each circuit drawing, identify the bulbs as being wired “in series” or “in parallel”.

b) Draw in the schematic diagram for each circuit in the spot provided under each circuit diagram.

c) Will bulb 1 and bulb 2 be brighter, the same brightness or dimmer than bulbs 3 and 4? ______Explain why. ______
______
______

d) If bulb 1 goes out, what will happen to bulb 2? ______Why? ______

e) If bulb 3 goes out, what will happen to bulb 4? ______Why? ______

f) List two reasons why parallel circuits are usually used in homes instead of series circuits.
______

e) Identify at least one disadvantage of parallel circuits compared to series circuits. ______
______
3. Look at the two circuits labelled A and B below.

a) In which circuit – A or B – would there be the greatestamount of current flowing? ______How do you know?
______

b) Ohm’s Law tells us that V = I x R. Use the values in each circuit to calculate the current in each one. The work has been started for you underneath each schematic diagram. Show your units!

4. Use the words in the word list to fill in the blanks below. Some words may not be used at all. Use a word only once.

nonrenewable / fuse / renewable / voltmeter / negative
circuit breaker / ammeter / grounded / positive

a) Current is measured in an electrical circuit using a(n) ______.

b) Voltage (potential difference) is measured in an electrical circuits using a(n) ______.

c) Fossil fuels like coal, gas and oil are examples of energy sources that are ______.

d) A ______contains a substance that melts when too much current is passing through a circuit. This breaks the circuit and the current stops.

e) The third prong in a plug is important to make sure current is ______if an electrical device is damaged.

f) Electrons flow from the ______terminal of a power source to the ______terminal.

g) A GFCI is often used in an area of the house where there is water. It is a special electrical outlet that has a ______built right in to detect very small changes in current.

5. Refer to the circuit drawn below as you answer each question.

a)In the diagram, the switch is open. Are the light bulbs lit up? _____ Explain why or why not.

b)Are bulbs 1 and 2 wired together in series or in parallel?
______

c)Are bulbs 3 and 5 wired together in series or in parallel?
______

d)Are bulbs 3 and 5 wired to bulbs 4 and 6 in series or in parallel? ______

e)If the switch is closed,

  • will the light bulbs be lit or not? ______
  • list the light bulbs which will be the brightest. ______
    Explain why they are the brightest. ______
    ______
    ______
  • list the light bulbs which will be the dimmest. ______
    Explain why they are the dimmest. ______
    ______
  • Of the 6 light bulbs, there should be 2 left that you have not yet described in terms of their brightness. Which bulbs are these? ______Describe and explain the brightness of these bulbs compared to the other 4 bulbs in the circuit. ______
    ______

f)If the switch is closed and light bulb #1 is unscrewed, what will happen? ______
Why? ______
______

g)If the switch is closed and light bulb #3 is unscrewed, what will happen to light bulb #5? ______
Why? ______
What will happen to the other light bulbs? ______
Why?______

h)If the switch is closed and light bulb #6 is replaced by copper wire, what will happen to the other light bulbs? Explain your answer. ______
______

6. Use the words below to fill in the flowchart showing how electricity flows into your home.

Words:

distribution panel / home hydro pole / main breaker switch / electric meter
circuit breaker, fuses, GFCI devices / Wall outlets

7.Explain 4 influences that affect the resistance of a transmission wire as it sends electricity from a generating station to your home.

1)

2)

3)

4)

8.You have 4 pith balls. They are labelled A, B, C, D. You have been told that each one has either a positive or a negative charge. You have also been told that Ball A is positively charged. You do some experiments to see if you can figure out whether each of the other balls carries a positive charge or a negative charge. The diagrams labelled 1, 2, 3 below show your observations. Identify the charge on Balls B, C and D.

Charge on Ball B = ______

Charge on Ball C = ______

Charge on Ball D = ______