Term: 2^{nd} Term
Week: 8
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Physics
Topic: Arrangement of resistors
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures
INSTRUCTIONAL PROCEDURES
PERIOD 12
PRESENTATION 
TEACHER’S ACTIVITY 
STUDENT’S ACTIVITY 
STEP 1 INTRODUCTION 
The teacher reviews the previous lesson on Verification of the ohm’s law 
Students pay attention 
STEP 2 EXPLANATION 
He states and explains the types of arrangement of resistors

Students pay attention and participates 
STEP 3 DEMONSTRATION 
He states and explains the factors affecting electrical resistance

Students pay attention and participate 
STEP 4 NOTE TAKING 
The teacher writes a summarized note on the board 
The students copy the note in their books 
NOTE
ARRANGEMENT OF RESISTORS
There are two arrangement of Resistor, which are:
SERIES ARRANGEMENT:
When the resistor is connected end to end as shown, they are said to be in series connection
For series connection, each Resistor (R) has different Voltage (V) but the same Current (I) The total Voltage (V) in the Circuit is given as
V= V1+V2+V3……… (x)
From Ohm’s Law V = IR
Which gives,
IR =IR1+IR2+IR3
IR = I (R1+R2+R3)
Therefore the equivalent resistance (R) of the combination is given by
R = R1+R2+R3
PARALLEL ARRANGEMENT
When resistor is arranged side by side such that their corresponding ends join together at two common junctions, the arrangement is known as parallel arrangement.
The combined or equivalent resistance (R) is given by R1
For parallel connection, each Resistor (R) has different current (I) but the same Voltage (V)
The total Current in the Circuit is given as
I = I1+I2+I3…… xx
From Ohm’s Law V = IR
So, I = V
R
Which gives, V =( V + V + V)
R R1 R2 R3
_{ }
Therefore the equivalent resistance of the combination is given by
_{ }
𝑉𝑅 = v(1 + 1 + 1)
𝑅1 𝑅2 𝑅3
Therefore the equivalent resistance of the combination is given by
𝟏𝑹 = 𝟏 + 𝟏+ 𝟏
𝑹𝟏 𝑹𝟐 𝑹𝟑
Example: Find the equivalent Resistance in the Circuit below
Solution:
Solution:
Two 2Ω Resistors are connected in series with 3Ω and 5Ω resistor.
Calculating the two parallel connected resistors:
R1= 2Ω and R2= 2Ω
1 = 1 + 1
𝑅 2 2
1 = 1
𝑅 1
R = 1Ω
The circuit diagram becomes,
Now calculating the series connection of the resistor:
R = R1+R2+R3
R=3+1+5
R=9Ω
FACTORS AFFECTING ELECTRICAL RESISTANCE
EVALUATION: 1. State and explain the two types of resistor arrangement
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively