Page 8 - Physics_Form_2

Physics for Secondary Schools

negatively charged) and the other to lose
Static electricity results from the electrons (becoming positively charged).
accumulation of static electric charges Common examples include rubbing a
on a material that does not conduct glass rod with cloth (Figure 1.2 (a)), and
electricity. walking across a carpet (Figure 1.2 (b))
or rubbing a balloon with woollen cloth
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Generating static electricity (Figure 1.2 (c)). The magnitude of the
static charge depends on several factors,
Static electricity is generated through the including the materials involved, the
transfer of electrons between materials. surface properties, and the environmental
This happens when two objects come conditions, such as humidity. This
into contact and are separated, causing charge build-up can lead to electrostatic
one material to gain electrons (becoming discharge, such as a spark.

Uncharged Uncharged Charged glass rod
silk cloth glass rod

Charged
silk cloth

Before rubbing After rubbing Before walking After walking
(a) Rubbing a glass rod with silk (b) Walking on the carpet

Balloon Woollen cloth Balloon Woollen cloth

Before rubbing After rubbing
(c) Rubbing a balloon with a woollen cloth

Figure 1.2: Generating static charges
Activity 1.1

Aim: To demonstrate the charging of an object
Materials: Wool jumper, dry plastic sheets

Procedure
1. Align two transparent plastic sheets on top of a book.
2. Rub the two plastic sheets with the wool jumper several times.

2
Student’s Book Form Two

Physics Form 2 Final.indd 2 25/10/2025 10:25