Why Placing Wires Correctly on a Light Bulb Is Important for the Successful Lighting of the Bulb
Summary
Using this activity, students should discover why wires need to be placed on the side of a light bulb and on the bottom of a light bulb in order for it to light. The students will complete a simple circuit using a battery, 2 wires, and a bulb. To understand how the light bulb becomes part of the simple circuit, the students will investigate the structure of a light bulb by looking inside a larger bulb. The students will then diagram the bulb's structure and the flow of electricity through that simple circuit (including the bulb, the wires, and the battery).
CollapseLearning Goals
- Students will discover how an electric current travels through a light bulb as part of a simple circuit.
- Students will be able to explain why it is important to contact a wire at the bottom of a light bulb and on the metal side of a light bulb.
- Students will diagram the inside structure of a light bulb and will trace the flow of electricity through the light bulb as part of a simple circuit.
- Vocabulary: simple circuit, current, filament
- Students will be able to explain why it is important to contact a wire at the bottom of a light bulb and on the metal side of a light bulb.
- Students will diagram the inside structure of a light bulb and will trace the flow of electricity through the light bulb as part of a simple circuit.
- Vocabulary: simple circuit, current, filament
Context for Use
This activity could be used in your classroom (Grades 3-6) at the introductory level of simple circuits. The entire activity should take about 30-45 minutes. Class size could vary. You could have students work individually or in small groups. It is an activity that is a simple, hands-on student discovery and is an eye-opener to how an electric current travels through a light bulb.
Materials needed:
Preparation: The teacher should remove the outer glass from several large light bulbs (one for each small group would save on the number of bulbs needed)
Other materials needed (per student or per small group):
2 wires
1 battery
1 small light bulb
battery holder (if available)
tape to hold wires (if battery holder is not available)
Once the students discover and discuss the operation of a simple circuit using the smaller light bulb, they should be ready for the main part of this activity (looking at the inside structure of a light bulb).
Materials needed:
Preparation: The teacher should remove the outer glass from several large light bulbs (one for each small group would save on the number of bulbs needed)
Other materials needed (per student or per small group):
2 wires
1 battery
1 small light bulb
battery holder (if available)
tape to hold wires (if battery holder is not available)
Once the students discover and discuss the operation of a simple circuit using the smaller light bulb, they should be ready for the main part of this activity (looking at the inside structure of a light bulb).
Description and Teaching Materials
Preparation: The teacher should remove glass from several large light bulbs (one for each small group)
Other materials needed (per student or per small group):
2 wires
1 battery
1 small light bulb
battery holder (if available)
tape to hold wires (if battery holder is not available)
The students will first try lighting a bulb with a battery, 2 wires, and a small bulb. Once this is successful for all, discuss (or review) how a simple circuit works.
Next, without previous instruction, ask what they know about a light bulb. "How does the flow of electricity to the bulb light the light bulb?" To help the students begin to understand this, they will need to see where the current goes through the bulb. To save on light bulbs, I would divide your class into small groups. Provide each small group of students with a light bulb that has the outside glass removed. (To better investigate the structure of a light bulb, you should use the bigger, standard household light bulbs.) Have them observe the inside of the light bulb to see where the wires need to contact the light bulb and ask: "Why there?"
By investigating the inside structure of the light bulb, they should realize that one wire in the light bulb is attached to the metal side of the bulb and then to the filament. Another wire helps complete the circuit in the bulb by attaching to the filament and then down to the base of the bulb. This discovery should help them understand how the current can travel in and out of the bulb to keep the simple circuit complete as it lights the bulb. More investigation and discussion is needed to explain the lighting of the filament in the bulb.
Once the structure of the light bulb is observed, discussed, and understood, a diagram of the inside of the light bulb, the wires, and the battery could be drawn and labeled. The flow of current should then be added to the diagram.
(See: http://home.howstuffworks.com/light-bulb1.htm)
You could extend this activity by looking at the inside of a flashlight and trying to discover how the light bulb lights in a flashlight. A diagram of the simple circuit within the flashlight could be drawn.
Other materials needed (per student or per small group):
2 wires
1 battery
1 small light bulb
battery holder (if available)
tape to hold wires (if battery holder is not available)
The students will first try lighting a bulb with a battery, 2 wires, and a small bulb. Once this is successful for all, discuss (or review) how a simple circuit works.
Next, without previous instruction, ask what they know about a light bulb. "How does the flow of electricity to the bulb light the light bulb?" To help the students begin to understand this, they will need to see where the current goes through the bulb. To save on light bulbs, I would divide your class into small groups. Provide each small group of students with a light bulb that has the outside glass removed. (To better investigate the structure of a light bulb, you should use the bigger, standard household light bulbs.) Have them observe the inside of the light bulb to see where the wires need to contact the light bulb and ask: "Why there?"
By investigating the inside structure of the light bulb, they should realize that one wire in the light bulb is attached to the metal side of the bulb and then to the filament. Another wire helps complete the circuit in the bulb by attaching to the filament and then down to the base of the bulb. This discovery should help them understand how the current can travel in and out of the bulb to keep the simple circuit complete as it lights the bulb. More investigation and discussion is needed to explain the lighting of the filament in the bulb.
Once the structure of the light bulb is observed, discussed, and understood, a diagram of the inside of the light bulb, the wires, and the battery could be drawn and labeled. The flow of current should then be added to the diagram.
(See: http://home.howstuffworks.com/light-bulb1.htm)
You could extend this activity by looking at the inside of a flashlight and trying to discover how the light bulb lights in a flashlight. A diagram of the simple circuit within the flashlight could be drawn.
Teaching Notes and Tips
I have taught simple circuits many times using a light bulb as one of the tools. I knew the students had to touch the metal side and bottom of the bulb to make it light but this activity helps the students discover and understand why those two contacts are important.
Safety tips: Teachers should remove the outer glass of the light bulb, not the students. Make sure kids handle the large, open light bulbs carefully. Be careful of sharp edges. DO NOT allow students to hook these open light bulbs to a current.
Safety tips: Teachers should remove the outer glass of the light bulb, not the students. Make sure kids handle the large, open light bulbs carefully. Be careful of sharp edges. DO NOT allow students to hook these open light bulbs to a current.
Assessment
- Observe their hands-on work (making a light bulb light using 1 battery, 2 wires, and 1 bulb to complete a simple circuit)
- Students' diagram of a light bulb's inner structure
- Students' diagram of battery, wires, big bulb with inside structure, and the tracing of current through that simple circuit connection
- Students' diagram of a light bulb's inner structure
- Students' diagram of battery, wires, big bulb with inside structure, and the tracing of current through that simple circuit connection
Standards
4.II.C.1—simple circuits