Simple Electric Circuits

Simple electric circuits

1. A simple electric circuit is a closed path through which electric current flows to perform useful work such as lighting a bulb, running a fan, or powering a motor. For a circuit to work, all components must be properly connected to allow continuous flow of electric charges.
2. Basic circuit components
3. Below are the main components that make up a simple electric circuit:
4. Energy Source: This provides the electrical energy required for the current to flow. Common examples include cells, batteries, and power supplies.
5. Conducting Wires: These are the paths through which electric charges move. They are usually made of metals like copper, which is a good conductor of electricity.
6. Control Devices: These are components like switches that are used to control the flow of current. When the switch is open, the circuit is broken and no current flows. When it is closed, current flows through the circuit.
7. Load Devices: These are the parts of the circuit that consume electrical energy to perform work. Examples include:

• Bulbs (to produce light)
• Heaters (to produce heat)
• Motors (to produce motion)
• Resistors (to limit or control current)

viii. Measuring Devices: These are instruments used to measure the quantities in the circuit such as:

• Ammeter to measure current
• Voltmeter to measure voltage
• Multimeter to measure both voltage, current, and resistance

Circuit components, their purposes, and symbols

Circuit Device	Purpose	Symbol
Connecting wire	Carries electric current
Wire joined	Indicates wires joined together
Wire crossing (not connected)	Wires cross without connection
Cell	Provides electrical energy (1.5V)
Battery (4 cells)	Provides more electrical energy than a single cell
AC power supply	Supplies alternating current
Bulb (lamp)	Converts electricity to light
Resistor	Limits current flow
Switch (open)	Opens or closes the circuit
Rheostat (variable resistor)	Controls the amount of current
Galvanometer	Detects small current
Ammeter	Measures electric current
Milliammeter	Measures small electric current
Multimeter	Measures current, voltage, and resistance
Voltmeter	Measures potential difference
Capacitor	Stores electric charge

Potential difference (voltage)

• The potential difference (P.D.), also called voltage, is what pushes electric charges through a circuit.
• It is measured in volts (V) using a voltmeter.
• The potential difference exists between the positive and negative terminals of a power source.
• Current flows when a conducting path connects the terminals.