Four Simple Concepts About Electrical Safety

  1. Electricity travels in a closed loop called a circuit.
  2. Electricity flows easily through conductors, not through insulators.
  3. Electricity always takes the easiest path to the ground.
  4. Water is an excellent conductor of electricity. Because the human body is mostly water, we are also good conductors of electricity.

The discovery guide introduces these principles and applies them to many different situations.

Concept Matrix

Use this matrix to find where basic and supplementary concepts are illustrated in the booklet.
MAIN CONCEPT FOUND ON PAGE (I=Introduced R= Reinforced)
2 3 4 5 6 7 8 9 10 11 12 13 14 15
1. Electricity travels in a closed path called a circuit I R I                      
2. Electricity flows easily through conductors, not through insulators.   I R R R R       R R   R R
3. Electricity always takes the easiest path to the ground. If you become part of that path, you will be injured.     I R R R R R R   R   R R
4. Water is an excellent conductor of electricity. Because the human body is mostly water, we are also good conductors of electricity.       I   R R       R     R
5. Effects of contact with electricity.     I       R             R
6. Electricity is measured in volts, watts and amps.     I       R       R      
7. Kinds of electrical equipment, their dangers and safe behavior.               I R I       R
8. What to do in an electrical fire or other electrical emergency.                     I I I R

Process Skills

  1. Predicting what is likely to happen in situations involving possible electrical contact
  2. Tracing or drawing the path electricity travels
  3. Identifying conductors and insulators
  4. Explaining the effects of contact with electricity
  5. Inferring that although a situation may not actually result in injury, danger from electricity is always present
  6. Describing the effect of water in situations involving electricity
  7. Converting units of measure
  8. Applying what they know to new situations in order to identify proper, safe behavior

Learning Strategies

  1. Students read information and do activity individually
  2. Students work with partners or in small groups.
  3. Students discuss information, ideas, and/or answers as a class.

Questions For Review & Assessment

  1. Can you trace or describe the path electricity travels in this picture? Pg. 2, 4-7 (Electricity either will travel in a closed circuit or will find its way to the ground through a person or another conductor that comes between electricity and the ground. Students should be able to identify the points of contact and the path electricity would take.)
  2. Which materials are insulators? Which ones are conductors? Pg. 3, 11
  3. What happens if you get between electricity and the ground? Pg. 4,6, 8, 9,10, 12 (Because a person either has come into contact or could possibly contact electricity, giving it a path to the ground. By its nature, electricity is attracted to the ground.)
  4. Why is there danger of electrical shock in the situation portrayed? Pg. 4-7, 8, 10-12 (Because a person either has come into contact or could possibly contact electricity, giving it a path to the ground. By its nature, electricity is attracted to the ground.)
  5. Can you describe a similar situation in which there is danger of contact with electricity? Pg. 4-7, 9, 10, 12-15 (Student answers will vary, but must include a point of contact with electricity and with the ground.)
  6. Why are we almost always at risk of electrical shock? (Because we are good conductors and because we are almost always touching the ground.)
  7. Describe a safe alternative to the situation shown/discussed. Pg. 4-7, 9-11, 15 (Students answers will vary and may include both general and specific safety "rules" such as: Keep water and electricity apart; fly kites far away from power lines; be sure the insulation around the power cord to an appliance is not frayed or broken.)
  8. Describe proper precautions to take to avoid becoming part of electricity's path to the ground. Pg 4-7, 9-15
  9. List three steps to take in event of an electrical fire or electrical emergency. Pg. 13 (In case of electrical fire: leave the area; telephone for help from a safe location or tell an adult; tell an adult to use a proper chemical fire extinguisher on the fire. In case of electrical emergency: tell an adult to pull the plug or turn off the power at the circuit breaker/fuse box; call for help; when you are SURE all danger is gone, give first aid.)
  10. What may be the hardest thing to remember in an electrical emergency? Pg. 12-14 (That the best help may be to stay away from the victim or the scene to avoid becoming part of electricity's path to the ground.)

Supplementary Approaches

To bolster student understanding or to take them deeper into the information, here are a few other activities and approaches to learning.
Main Concept
Pages 2, 3, 4
Supplementary Approaches
Page 2

Electricity travels in a closed path called a circuit.

 

Ask students to describe the path electricity travels to get to the lights in the classroom and back to the distribution grid.

 
Main Concept
Pages 4, 5, 6, 7, 8, 9, 10, 12, 14, 15
Supplementary Approaches
Page 7

Electricity always takes the easiest path to the ground. If you become part of that path, you will be injured.

 

Ask students to find a way to not touch the ground. Remind them about insulators and how they might be useful in this situation. [Students might suggest standing on a fiberglass mat, wearing rubber soled shoes (not athletic shoes), or some way to hold a layer of air between them and the ground.]

 
Main Concept
Pages 5, 7, 8, 12, 15
Supplementary Approaches
Page 3

Water is an excellent conductor of electricity. Because the human body is mostly water, we are also good conductors of electricity.

 

Water is such a good conductor that most insulators will not work if they are wet. Have students wet their best insulator from their experiment, observe what happens, and explain why it happened.

 
Page 7

Ask students to locate GFCIs in your classroom or school. What conclusions can they draw about where GFCIs are placed? (GFCIs are used outdoors and inside near water because those are the areas of greatest risk of contact.) Have they seen GFCIs embedded in appliance cords? Why are they placed there? (To perform the same function as a GFCI in the wall.) What kind of appliances are most likely to have a GFCI in the power cord? (Those to be used around water.)

 
Main Concept
Pages 4, 8, 12
Supplementary Approaches
Page 4

Electricity is measured in volts, watts, and amps

 

To understand the relationship of Amps, Watts, and Volts, explain to students that electricity flowing through a wire is like water flowing through a garden hose. The amount of water depends on the diameter of the hose (amps). The pressure of the water depends on how far open the faucet is (volts). The amount of work that can be done (watts) depends on both volts and amps.

Have students test several drinking straws with different diameters. How hard do they have to suck to drink the same amount of water? Does the diameter affect how long it takes to drink the water?
Page 8

Watts = Volts x Amps. Assume you have a 1000 W hairdryer plugged into a 120 V circuit. How much amperage is available? (1000/120mA/A = 8000 mÅ. Effect is Probably Fatal.)

 
Main Concept
Pages 9, 10, 11,12, 15
Supplementary Approaches
Page 9
Identifying kinds of electrical equipment, their dangers and safe behavior Supplementary Approaches
Take students outside the school building and locate lines, transformers, and entrance of electrical lines into buildings. What other equipment can they see? (Probably the electric meter.) What is it used for? (To measure how much electricity is used in the building.)
Page 10
Ask students to draw a map of their route to school. Mark the places where electrical equipment is placed (including overhead lines). Indicate places where there is danger of electrical contact.
Page 11

Ask your local electric company to send someone to your school to demonstrate safety equipment used by lineworkers.

 
Main Concept
Pages 12, 13, 14
Supplementary Approaches
Page 12
What to do in an electrical fire or other electrical emergency Ask students to go home and practice safe behaviors around downed power lines with their families.
Page 13

In case of fire, ask students to plan an emergency escape route with their families. Ask them to draw a map of the route and share it in class with a small group. What features do different plans have in common?