Table of Contents
IGCSE Coordinated Science: Introduction to Electricity
1. Demonstrate understanding of current, potential difference, e.m.f. and resistance, and use with their appropriate units.
Electric Current:
- Is the flow of electric charge within a circuit.
- Is measured in amperes or amps (A).
- Represents how much electric charge is passing a single point in the circuit in moment.
- Does not run out in a circuit i.e. current is the same at the beginning and end of a circuit.
Potential Difference:
- Difference in potential between two points of a circuit.
- Potential represents how much energy (joules per coulomb) there is to drive a current through the wire and is measured in volts (v)
e.m.f:
- Electro-motive force (e.m.f) is the voltage (potential) that a battery will supply. It is the driving force that gives the electrons the energy to move around the circuit.
Resistance:
- Is a measure of how difficult it is to push a current through a circuit.
- Is measured in Ohms (Ω)
2. State that charge is measured in coulombs (C)
Charge is a property that certain particles have that can have a force of repulsion or attraction (like electrons or ions).
The unit for electrical charge is Coulombs (C).
3. Use and describe the use of an ammeter and a voltmeter
Ammeter:
- Is a device used to measure the amount of current flowing through the circuit (in amps)
- Has to connected in series to the circuit
Voltmeter:
- Is a device used to measure the potential difference between two points in a circuit.
- Has to be connected in parallel to the component you want to measure.
