Basic Electricity - Senior Secondary 1 - Direct current sources of battery

TERM: 3^RD TERM

WEEK SEVEN

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject: BASIC ELECTRICITY

Topic: DIRECT CURRENT SOURCES OF BATTERIES

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Define a battery

II.) Identify the symbol for battery

III.) State the types of cells

IV.) Discuss the operation of the cell

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION	TEACHER’S ACTIVITY	STUDENT’S ACTIVITY
STEP 1 INTRODUCTION	The teacher explains the meaning of a battery and draw out the symbol of a cell	Students listens attentively to the teacher
STEP 2 EXPLANATION	Teacher highlights and describes the types of cells, also discussing the operations of the cells	Students exhibit attentiveness and active engagement
STEP 3 NOTE TAKING	The teacher writes a summarized note on the board	The students copy the note in their books

NOTE

DIRECT CURRENT SOURCES OF BATTERIES

A battery is a device that converts chemical energy into electrical energy through electrochemical reactions. It consists of one or more electrochemical cells connected in series or parallel to provide a steady flow of electric current.

Symbols of a battery

The symbol for a battery typically consists of one or more cells connected in series, represented by parallel lines indicating the positive and negative terminals. The longer line represents the positive terminal (+), and the shorter line represents the negative terminal (-).

Types of cells

Primary Cells: These are non-rechargeable cells that generate electricity through irreversible chemical reactions. Once depleted, they cannot be recharged. Examples include alkaline batteries and zinc-carbon batteries.
Secondary Cells (Rechargeable Cells): These are cells that can be recharged by passing electric current through them in the opposite direction of discharge. They undergo reversible chemical reactions. Examples include lithium-ion batteries, nickel-metal hydride (NiMH) batteries, and lead-acid batteries.

Operation of the cell

The operation of a cell involves electrochemical reactions that occur between the electrodes (anode and cathode) and the electrolyte. Below is how a cell works:

Chemical Reaction at Electrodes:

- At the anode (negative electrode): Oxidation occurs, where electrons are released from the anode material and flow through the external circuit to the cathode.

- At the cathode (positive electrode): Reduction occurs, where electrons from the external circuit combine with ions from the electrolyte to form new compounds.

Flow of Electrons:

- Electrons flow from the anode through the external circuit to the cathode, generating an electric current.

- The flow of electrons through the external circuit can be used to power electrical devices.

Ion Migration in Electrolyte:

- Ions from the electrolyte migrate through the electrolyte towards the electrodes to balance the charges generated by the electron flow.

- This ion migration maintains the chemical balance within the cell, allowing the electrochemical reactions to continue.

Generation of Electrical Energy:

- The continuous flow of electrons from the anode to the cathode generates electrical energy, which can be used to power various devices connected to the battery

EVALUATION: 1. Define a battery

State the 2 types of cells and explain them
Discuss briefly the operation of the cells.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively