Experiment: Charges between charged bodies

Aim: To demonstrate the forces of static electricity

Materials: glass/perspective rod, 2 polythene rods, silk cloth, woolen cloth and 2 watch-glasses

Method

1. Balance two watch-glasses so that the top one is sitting on an inverted one at the bottom
2. Rub the glass/perspex rod with the silk clot and place it on top of the watch glasses
3. Rub the polythene rod with the wool
4. Bring the charged polythene rod near the charged glass rod and observe what happens
5. Remove the charged glass rod
6. Rub another polythene rod with wool and place it on the top watch-glasses
7. Bring the charged polythene and observe what happens

Results and Observations

• Rubbing the glass/perspex rod with silk gives it a positive charge
• Rubbing the polythene rod with wool gives it a negative charge
• When the negatively charged polythene is brought near the positively charged perspex/glass rod the glass/perspex rod is attracted (it moves slightly towards the polythene) by the polythene rod
• When two polythene rods are used they repel each other

Conclusion

• Like charges repel each other
• Unlike charges attract each other

To access more topics go to the Combined Science Notes page.