Design and Construction of a Variable Resistance Box

ABSTRACT

In this project a resistance box has been constructed using locally available materials namely, 1/3 and plywood for the construction of the box, cupper wire, Ferro board, soldering iron, soldering lead, screw and resistors. The resistance obtainable from the box ranges from 2-11W. The box is fitted with terminal s to allow easy use in physics laboratory practical. At the end of the experiment, the values obtained are very close to those obtainable using imported box.

TABLE OF CONTENT

Title page                                                                                             i

Certification                                                                                          ii

Dedication                                                                                            iii

Acknowledgment                                                                                 iv

Abstract                                                                                                v

Table of content                                                                                  vi

CHAPTER ONE

1.1     Introduction                                                                                1

1.2     Aim of the project                                                                      2

CHAPTER TWO

2.1     Resistor                                                                                      3

2.2     Theory of operation                                                                  4

2.3     Classification of resistors                                                         7

2.4     Factor affecting resistances                                                    12

2.5     Reactivity and conductivity                                                      13

2.6     Resistor colour codes                                                               15

2.7     Symbols of resistor across battery                                          17

2.8     Uses of resistors in a circuit                                                    19

CHAPTER THREE

3.1     Design and construction                                                          20

3.2     Other components of the box                                                  21

CHAPTER FOUR

4.1     Test and experiments                                                               23

4.2     The box in a simple circuit                                                       24

4.3     Discussions                                                                               26

CHAPTER FIVE

5.1     Summary                                                                                    27

5.2     Conclusion                                                                                 28

5.3     Recommendation                                                                      29

References                                                                                30