Science 10 Electricity & Magnetism Review Name: __________

(Worksheet) Date: __________

Block: __________

The following prescribed learning objectives will be tested on the provincial exam. Use the following as a guide to help you review for the exam. Be sure to use information in your Data Booklet to help you answer some of the questions

It is expected that students will:

10E1 state the relationships between charged objects

10E2 demonstrate how electricity results from the movement of charged particles such as electrons and ions

· current and static electricity

10E3 describe the interactions between magnetism and electricity and relate these to common devices

· common devices include motors, generators and solenoids

10E4 use apparatus to determine the relationships between current, voltage, and resistance in different types of circuits

· relating to Ohm’s Law

· correct placement of apparatus in a circuit

10E5 relate power and energy to common electrical devices

10E6 describe the distribution and safety considerations of electricity from its generated source to its use within the home

· including step-up and step-down transformers

· focus on distribution and safety considerations

10E7 apply knowledge and data to make recommendations for reducing energy waste

Part A – Static and Current Electricity

1. Fill in the blanks.

a) Two negatively charged objects __________________repel each other.

b) Two positively charged objects ___________________ repel each other.

c) A positively charged object and a negatively charged object are _______________ attracted to each other.

d) A negatively charged object and positively charged object are ________________ attracted to each other.

e) Charged objects are _____________________attracted to neutral objects.

2. A balloon is rubbed with some hair and some electrons are transferred to the balloon from the hair.

a) What is the resulting charge on the hair? _____________________ positive

b) What is the resulting charge on the balloon? ___________________ negative

c) Are protons transferred to the hair? ________________________ No (protons do not move)

3. Use the following diagram to answer the questions below.

A B

a) What is the charge on stick A? _________________________________ positive

b) What is the charge on stick B? _________________________________ no charge - neutral

c) Is stick A attracted to or repelled from stick B? ____________________ yes

4. Conductors/Insulators.

a) A conductor _____________can not hold static electric charge because electrons ____________can easily move through these types of materials.

b) An example of a good conductor is ______________________________ copper wire (any metal would be a good choice).

c) An insulator ___________can hold static electric charge because electrons ____________can not easily move through these types of materials.

d) An example of a good insulator is ________________________________plastic, wood, rubber (other answers are acceptable).

5. How is static electricity different from current electricity? ________________________________

_______________________________________________________________________________ Static electricity is a build up of charge that is non-moving once generated. Current electricity is generated by moving electrons.

6. Vocabulary. Fill in the Blanks with the words below. Not all words are used and some words can be used more than once!

Coulomb (C) Volt (V) ampere (A) resistor potential energy Voltmeter ammeter ohm (W)

electrical potential energy Ohm’s law electric circuit battery

chemical cell Series circuit schematic diagram series

terminals Parallel circuit series-parallel circuit parallel

voltage electric current resistance load

a) To measure current, the ______________________ammeter must be connected in _____________series with the battery or cells.

b) In order to measure the voltage or voltage drop you must connect the

_____________________voltmeter in _______________________parallel.

c) _______________Electric __________________current is the measure of electron flow (how many electrons pass through a point in one second).

d) An ____________________ampere/amp is equal to 1 Coulomb of charge per second.

e) In order for electricity to flow, an _______________ electric __________________circuit must have complete or closed pathway for electrons to flow.

f) This law states that voltage is proportional to current: _______ ________ Ohm’s Law.

g) ___________________Resistance is a measure of how hard it is for an electric current to flow through a material.

h) ___________________Voltage is the amount of electrical potential energy per Coulomb of charge transferred (or electrons).

i) A ________________coulomb is simply a large amount of charge that can be negative or positive. 6.24 x 10¹⁸ electrons would be equal to 1 ____________ coulomb of negative charge.

j) A _____________ battery is two cells linked together.

k) A _______________ chemical ____________ cell is an apparatus that generates electric current by a chemical reaction.

l) A ________________ series ________________ circuit only allows electrons to flow through one pathway. A______________________parallel ____________________ circuit allows electrons to flow through more than one pathway.

m) A __________________resistor is designed to regulate or control the amount of current flowing in a circuit.

n) A __________________load is anything that provides resistance in an electrical circuit. It uses and reduces the current in order to do some work.

o) A safety device that causes a break in the circuit when the current is too high is called a __________________________________fuse.

p) The unit of resistance is called the ______________ ohm (Ω).

q) A _______________Schematic _______________diagram is a representation of a circuit using symbols.

7. Use the following diagram to answer the questions below.

a) Which of the diagrams above demonstrates the movement of charged particles? ____________________________________________ I, II, III

b) Which of the diagrams above demonstrates no movement of charged particles? ____________________________________________ IV

8. Ohm’s Law. Calculate the unknown value using Ohm’s Law. Watch your units.

a) R = 25 W I = 8.0 A V = ? _________ 200 V

b) R = ? I = 8.0 A V = 12.5 V _________0.16 Ω

c) R = 40 W I = ? V = 400 V _________10 A

d) R = ? I = 800 mA V = 60 V _________75 Ω

e) R = 15 W I = 25OO mA V = ? _________375 Ω

f) R = 12 W I = ? V = 48 V _________4 A

g) R = 12 W I = 18 A V = ? _________216 V

h) R = ? I = 12 A V = 16 V _________1.33 Ω

i) R = 12.5 W I = ? V = 32 V _________2.56 A

j) R = ? I = 36 A V = 96 V _________2.67 Ω

9. Determine the total voltage produced by the following batteries/cells.

Each cell gives 1.5 V.

1.

Voltage= __________1.5 V

2.

Voltage= __________4.5 V

3.

Voltage= __________1.5 V

10. Use the diagram below to answer the following questions. Each cell gives 1.5 V.

a) Draw in an ammeter placed in the correct place.

b) Draw in a voltmeter measure the voltage of the cells.

c) Draw in a voltmeter to measure the voltage drop of one of the light bulbs.

d) In the blank, indicate if the following statements are supported, refuted, or neither supported nor refuted by the diagram above:

1. The lamps are connected in series. _________________________refuted

2. Total voltage produced by the dry cells is 3.0 volts. _____________supported

3. The current running through one lamp is different than the current running through the resistor._______________________________ supported

11. Sketch a graph that best describes the relationship between voltage and current when resistance is kept constant. Label your axes and include units.

12. Use the following diagram to answer the following questions. The two resistors are connected in parallel to a 6 V battery and the total current in the circuit is 4.5 A.

a) Calculate the total resistance (2 W and 4 W combined). 1.33 Ω

b) Use Ohm’s law to calculate the current running through the 2 W Resistor. 3 A

c) Use Ohm’s law to calculate the current running through the 4 W Resistor. 1.5 A

d) What does the current running through the two parallel branches added up to? How does this value compare to the total current in the circuit?

____________________________________________________________________________________________________________________ 4.5 A the value is the same as the total current of the circuit.

Part B – Work, Power, Energy & Magnetism

13. Calculate the Power used by a Portable CD player if it uses a 9 volt battery and 2 amps of current. 18 W

14. In a circuit, a 2 W resistor uses 5 A of current flowing through it for 10 minutes. How much energy is used by the circuit? 30 000 J

15. Calculate the energy (in kWh) consumed by a 60 W light bulb if it is left on for 100 hours. If energy costs $0.05 per kWh, how much does it cost you if you left it this 60 W light bulb for 100 hours. 6.0 kW•h, cost = $0.30

16. The following two questions refer to this description. Your electric meter reads 48 987 kWh on March 1. Two months later the meter reads 49 567 kWh. The cost of energy is 5¢ per kilowatt-hour.

a) How much energy did you use during the two months? ________________580 kW•h

b) How much will your electricity bill be for the two month period? _________cost = $29.00

17. Describe ways to decrease your household electrical bill and conserve energy.

______________________________________________________________hang clothes to dry

______________________________________________________________close refridgerator door

______________________________________________________________turn off lights when not in use

18. What is a circuit breaker? __________________________________________

_______________________________________________________________

_______________________________________________________________a switch that turns off automatically if the current flowing through the circuit exceeds the preset limit (overloading the circuit)

19. What happens when you overload a circuit? _____________________________

_________________________________________________________________

_________________________________________________________________when you put too many appliances on an electrical circuit and it draws more current than the circuit can handle. Overloading the circuit can cause electrical fires.

20. Explain why current is transmitted to your home at a high voltage.

___________________________________________________________________________________________________________________________________________________________________________________________________Low current is transmitted at high voltage which prevents less heat energy loss due to friction.

21. Use the following diagrams to answer the questions below.

Label A Label B

a) Which of the Energuide labels indicates the appliance that costs the least to operate? ______________________________Label A

b) Which of the Energuide labels indicates the appliance that costs the most to operate? ______________________________Label B

22. Use the diagram below to answer the following questions.

Transformer is a device that raises or lowers the voltage in power lines.

a) Label W: _________________________________ Step-up transformer

b) Label X:__________________________________ Step-down transformer

c) Label Y: __________________________________ Step-down transformer

d) Label Z: __________________________________ Service panel (not a transformer)

23. Name the four magnetic elements?

_______________ ________________ ________________ ________________ Iron, nickel, cobalt, gadolinium

24. What is a magnetic field? ___________________________________________

_________________________________________________________________ The region around a magnet where its effects can be detected.

25. Draw a diagram to represent the domains of a material that is a magnet?

26. Describe how you would make a permanent magnet? ________________________ ______________________________________________________________. Taking a material made of iron, cobalt, nickel or gadolinium and placing it in a strong magnetic field so that the domains align within the material.

27. Magnetic lines of forces always travel from ____________ North to ______________ South.

28. Fill in the north and south poles on the following magnet pairs to get the indicated interaction.

Attraction Replusion

S N S N S N N S

Or Or

N S N S N S S N

29. What does a current traveling through an electrical conductor produce? ______________________________________________________________a magnetic field

30. What is a solenoid? _______________________________________________

_________________________________________________________________a coil of a conducting material wrapped around an iron core

31. The direction that conventional current flows is from the _________positive terminal to the __________negative terminal.

32. Electrons in a circuit flow from the __________ negative terminal to ________ positive terminal.

33. Use the right-hand rule to draw the direction of magnetic field on the following cross-sections of wire when a electric current is running through it.

counetclockwise clockwise

34. Use the right-hand rule to draw the magnetic lines of force and label the north and south poles.

35. A motor uses _________________ electrical energy to produce _______________ mechanical energy.

36. A generator uses _______________ mechanical energy to product _______________ electrical energy.

37. Name 3 devices that use and/or contain an electromagnet (solenoid).

_________________ _____________________ _______________________ door bells, telephones, motors