Electric Charge, Conductors, Insulators and Simple Electric Circuits
From a tiny transferred electron to a glowing lamp, electricity follows clear rules.
Big idea: Electric charge can be positive or negative. Charge may stay on an object as static electricity or move through a closed conducting path as electric current.
Learning goals
- describe attraction and repulsion between charges;
- distinguish conductors from insulators;
- identify a cell, wires, lamp and switch in a simple circuit;
- predict whether a lamp lights when a circuit is open or closed;
- follow safe low-voltage classroom practice.
Charge and interaction
There are two kinds of electric charge: positive and negative. Like charges repel; unlike charges attract. An object is electrically neutral when its positive and negative charges balance. During rubbing or contact, electrons may move from one material to another. Protons remain bound inside nuclei.
Remember: a charged object can attract a neutral object because charges inside the neutral material shift slightly.
Conductors and insulators
A conductor lets electric charge move easily; metals are common examples. An insulator strongly resists charge motion; dry plastic, rubber and glass are common examples. A metal wire carries current while its plastic coating keeps the current away from hands and neighbouring wires.
| Material role | Examples | Use |
|---|---|---|
| Conductor | copper, aluminium | wire core |
| Insulator | plastic, rubber, glass | cover and support |