Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 2nd Term
Week: 4
Age: 15 years
Duration: 45 minutes
Subject: Radio, Tv & Electronics
Curriculum Theme: Trade
Previous Lesson: Concept Of Emission: Applications In Electronics.
Topic: PHOTO-ELECTRIC DEVICES
Subject Matter: Definition of photo-electric devices, Applications of photo-electric devices

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define photo-electric devices.
State at least three applications of photo-electric devices.

Affective Domain:

Appreciate the importance of photo-electric devices in everyday technology.
Show interest in how light is used to control electronic systems.

Psychomotor Domain:

Identify examples of photo-electric devices when shown.
Describe simply how a photo-electric device can be used in an application.

Discuss with peers the common uses of photo-electric devices in their environment.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum (Radio, TV & Electronics for SSS).
National Unified Scheme of Work for SSS 1 Radio, TV & Electronics.
Practical Radio, TV & Electronics for Senior Secondary Schools, Book 1.
https://www.google.com/search?q=photo-electric+devices
https://www.youtube.com/results?search_query=photo-electric+devices

Instructional Materials

The teacher will teach this lesson with the aid of:

A photo sensor.
A light detector.
Pictures or diagrams of various photo-electric devices and their applications.

Rationale for the Lesson

This lesson helps pupils understand how light energy can be converted into electrical signals or used to control electronic systems. This knowledge is important for appreciating the technology behind many automated systems and modern gadgets in daily life.

Prerequisite/Previous Knowledge

Pupils have a basic understanding of light, electricity, and simple electronic components.

Lesson Content/Board Summary

PHOTO-ELECTRIC DEVICES

Definition of Photo-Electric Devices

Photo-electric devices are electronic components whose electrical properties change when exposed to light, or which convert light energy into electrical energy or vice-versa.

Applications of Photo-Electric Devices

The following are common applications of photo-electric devices:

Automatic street lighting systems.
Smoke detectors and fire alarms.
Security and burglar alarm systems.
Automatic door opening and closing systems.
Light meters in cameras.
Solar cells (photovoltaic cells) for generating electricity.
Remote controls for televisions and other appliances.
Optical fibre communication systems.
Counting objects on conveyor belts.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to mention places where light is used to control things, like automatic doors or street lights. The teacher then introduces the topic: “Photo-Electric Devices.”
Pupils’ Activity: Pupils respond to the questions and listen to the introduction.
Learning Point: Pupils are prepared for the lesson and connect the topic to real-life examples.

Step 2: Definition of Photo-Electric Devices

Time: 10 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines photo-electric devices, explaining that they are components affected by light or convert light to electricity. The teacher writes the definition on the board.
Pupils’ Activity: Pupils listen, take notes, and ask questions for clarification.
Learning Point: Pupils understand what photo-electric devices are.

Step 3: Display and Identification of Devices

Time: 10 minutes
Teaching Skill: Demonstration/Observation
Teacher’s Activity: The teacher displays a photo sensor and a light detector, explaining their basic function and how they react to light. The teacher encourages pupils to observe.
Pupils’ Activity: Pupils observe the devices, touch them if possible, and ask questions about their operation.
Learning Point: Pupils can identify and understand the basic working principle of some photo-electric devices.

Step 4: Applications of Photo-Electric Devices

Time: 10 minutes
Teaching Skill: Elaboration/Listing
Teacher’s Activity: The teacher explains various applications of photo-electric devices, providing examples from the board summary. The teacher encourages pupils to contribute examples they know.
Pupils’ Activity: Pupils listen, note down the applications, and mention other examples they know.
Learning Point: Pupils learn about the diverse uses of photo-electric devices in technology.

Step 5: Group Discussion on Applications

Time: 5 minutes
Teaching Skill: Collaboration/Discussion
Teacher’s Activity: The teacher divides pupils into small groups and asks them to discuss and list two new applications of photo-electric devices that were not mentioned.
Pupils’ Activity: Pupils discuss in groups and present their findings to the class.
Learning Point: Pupils reinforce their understanding of applications and develop teamwork skills.

Step 6: Lesson Summary

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher quickly reviews the key points of the lesson, reinforcing the definition and common applications of photo-electric devices.
Pupils’ Activity: Pupils listen and recall the main points of the lesson.
Learning Point: Pupils consolidate their understanding of the lesson content.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define photo-electric devices.
Mention three applications of photo-electric devices.
State two examples of photo-electric devices.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 1 minute
Teaching Skill: Assignment
Teacher’s Activity: The teacher gives pupils homework: “Research and write down how a solar cell works.” The teacher then dismisses the class.
Pupils’ Activity: Pupils copy the homework and prepare for the next class.
Learning Point: Pupils are encouraged to conduct further research on the topic.

Lesson Keywords

Photo-electric – Relating to the electrical effects of light.
Light sensor – A device that detects light.
Photocell – A common term for a photo-electric device whose resistance changes with light.
Automatic control – Systems that operate without human intervention, often using sensors like photo-electric devices.

Differentiation

For pupils who grasp the concepts quickly, the teacher can ask them to explain the principle behind one specific application. For those needing more support, the teacher will provide simplified definitions and more direct examples, focusing on identifying devices rather than explaining their detailed operation.

Note for teachers using this lesson plan

Ensure to bring actual photo-electric devices or clear visual aids to enhance understanding. Encourage practical questions and relate the topic to everyday experiences of the pupils. Emphasize safety when discussing any electrical components.