Types of Light Sources
Say: Let’s explore some common sources of light we use in our daily life.
Instruction: Display images of different sources, such as the sun, bulbs, candles, flashlights, etc.
Ask: Can you name the light source in each picture? Which one is the brightest and which one is the dimmest?
Instruction: Encourage students to discuss and share their answers with the class.
Measurement of Light Brightness
Say: We measure the brightness of it using a unit called lumens.
Ask: Can anyone tell me what lumens are?
Ans: Lumens measure the amount of light emitted from a source.
Say: The more lumens a light source emits, the brighter it appears.
Instruction: Show an image of two light bulbs with different lumens, such as a 40-watt and 100-watt bulb.
Ask: Which one do you think is brighter? Why?
Instruction: Discuss with students how the higher the wattage, the more lumens a bulb emits and the brighter it appears.
Factors Affecting Light Brightness
Say: There are various factors that can affect the brightness of a light source.
Instruction: Display an image of a flashlight.
Ask: What factors can affect the brightness of a flashlight?
Instruction: Encourage students to discuss and share their ideas.
Ans: The type and quality of the batteries, the condition of the bulb, and the size and design of the flashlight can all affect its brightness.
Real-Life Examples of brightness of light sources
Say: Now let’s look at some real-life examples of how the brightness of light sources can affect our daily lives.
Instruction: Display an image of a street lamp at night.
Ask: Why do you think street lamps are so bright? What purpose do they serve?
Ans: Street lamps are bright so that we can see the road and our surroundings clearly, which helps prevent accidents and promotes safety.
Instruction: Display an image of a dimly lit room.
Ask: What are some consequences of working or reading in a dimly lit room for long periods of time?
Instruction: Encourage students to discuss and share their ideas.
Ans: Straining the eyes, headaches, and difficulty focusing can all result from working or reading in a dimly lit room for extended periods.
Conclusion to brightness of light sources
Say: In conclusion, the brightness of light sources is an essential aspect of our daily lives. By understanding the types of light sources, how to measure their brightness, and the factors that affect it, we can make informed decisions and choose the most appropriate sources for different situations.
2023-03-20
