BASIC ELECTRICITY 1

TOPIC: BASIC COMPONENTS OF ELECTRIC CIRCUIT

ELECTRIC CIRCUITS

An electric circuit can be defined as the path provided for easy flow of electric current.  It is for conversion of the electric current into useful purposes such as lighting and heating.  An electric circuit is connected or fitted with devices that control and measure the current and energy used in the process.

Simple electric circuit

BASIC COMPONENTS OF ELECTRIC CIRCUIT

THE CELL OR BATTERY: The cell or battery is to push the free electrons around the circuit.  The work done when one coulomb of charge moves from one point to the other in the conductor is known as the potential difference (p.d).  It is measured in volts.  The instrument used for measuring the potential difference is called the voltmeter (v). The ammeter (A) is used to measure the current flow.  Current is represented by the symbol I and it is measured in Amperes.  The instrument used for measuring current is called the ammeter.

RESISTANCE AND E.MF

RESISTOR: This is a component that opposes the free flow of electrons in the circuit.  Resistance (R) is measured in Ohms (Ώ) using Ohmmeter.

E.M.F (Electromotive force):   this is the force that moves the electrons in the circuit.  It is represented with V and measured in voltage using a voltmeter.  It is the force that moves the current around the electric circuit

SOURCES OF E.M.F

1.         Dry cell or primary cell (1.5V each)
2.         Wet cell or secondary cell (12V each)

 ARRANGEMENT OF ELECTRIC CIRCUIT

Electric circuits can be arranged in the following ways

1.         Series arrangement (ii) parallel arrangement (iii) combination of series and parallel arrangement
2.         Series Arrangement

Parallel Arrangement

EVALUATION QUESTION

1.         (a) Define an electric circuit (b) Draw a simple electric circuit
2.         State the instrument used in measuring (i) potential difference (ii) current
3.         Define: (a) potential difference (b) E.M.F (c) state two sources of E.M.F