Electrical Quantities O Levels/IGCSE
Whatsapp wa.link/f330n7
Contact : +923092656780
Email : [email protected]
4.2 Electrical quantities
4.2.1 Electrical charge
1 State that there are positive and negative charges and that charge is measured in coulombs
2 State that unlike charges attract and like charges repel
3 Describe experiments to show electrostatic charging by friction
4 Explain that charging of solids by friction involves only a transfer of negative charge (electrons)
5 Describe an electric field as a region in which an electric charge experiences a force
6 State that the direction of an electric field line at a point is the direction of the force on a positive charge at that point
7 Describe simple electric field patterns, including the direction of the field:
(a) around a point charge
(b) around a charged conducting sphere
(c) between two oppositely charged parallel conducting plates (end effects will not be examined)
8 State examples of electrical conductors and insulators
9 Describe an experiment to distinguish between electrical conductors and insulators
10 Recall and use a simple electron model to explain the difference between electrical conductors and insulators
4.2.2 Electrical current
1 Define electric current as the charge passing a point per unit time; recall and use the equation electric current = charge
time I = Qt
2 Describe electrical conduction in metals in terms of the movement of free electrons
3 Know that current is measured in amps (amperes) and that the amp is given by coulomb per second (C / s)
4 Know the difference between direct current (d.c.) and alternating current (a.c.)
5 State that conventional current is from positive to negative and that the flow of free electrons is from negative to positive
6 Describe the use of ammeters (analogue and digital) with different ranges