Edexcel iGCSE Physics -2.23P Core Practical: Charging by Friction- Study Notes- New Syllabus

Practical: Charging Insulating Materials by Friction

Aim

To investigate how insulating materials can be charged by friction and to observe the effects of electrostatic charge.

Apparatus

• Plastic rod or balloon
• Dry cloth, wool, or hair
• Small pieces of paper OR pith balls
• Thread and stand (for suspending pith balls)

Method

• Ensure all materials are dry.
• Rub the plastic rod or balloon firmly with a dry cloth or wool.
• Bring the charged rod close to small pieces of paper.
• Observe what happens.
• Alternatively, bring the charged rod close to suspended pith balls.
• Allow the rod to touch the pith balls, then observe again.

Observations

• Small pieces of paper are attracted to the charged rod.
• Pith balls move towards the charged rod.
• After touching the rod, pith balls may be repelled.

Explanation

• Rubbing transfers electrons from one material to another.
• The plastic rod gains electrons and becomes negatively charged.
• The cloth or hair loses electrons and becomes positively charged.
• Neutral objects become polarized, causing attraction.
• After contact, like charges repel.

Conclusion

• Insulating materials can be charged by friction.
• Charging occurs due to the transfer of electrons.
• Electrostatic forces cause attraction and repulsion.

Safety

• Use dry hands and dry materials.
• Avoid humid conditions.
• Do not rub near sensitive electronic equipment.

Improving Accuracy

• Repeat the experiment several times.
• Ensure consistent rubbing time and pressure.
• Use lightweight paper or freely suspended pith balls.

Key Idea

• Only electrons move during charging.
• Insulators hold static charge.
• Like charges repel; unlike charges attract.