Investigating Static Electricity Flashcards
How can you investigate static electricity
When a polythene rod is rubbed with a duster, electrons move from the duster to the rod, causing the duster to become positively charged, and the rod to become negatively charged
When an acetate rod is rubbed with a duster, electrons move from the rod to the duster, causing the duster to become negatively charged, and the rod to become positively charged
You can prove this with either the gold-leaf electroscope method or the suspended charged rod method
Explain the process of the gold-leaf electroscope method
An electroscope has a metal disc connected to a metal rod with two pieces of gold leaf attached to it
When a rod with a charge is brought near to the disk of the electroscope, electrons will either be attracted or repelled
This induces a charge in the metal disk which induces a charge in the gold leaves, both leaves will have the same charge so will repel each other, causing them to rise
When the rod is taken away, the gold leaves will discharge and fall again
Explain the process of the suspended charged rod method
Suspend a charged rod with a know charge on a thread
Use the rod with an unknown charge and see if there is repulsion or attraction
If there is attraction, then the rods have opposite charges, if there is repulsion, then the rods have equal charges
How do Van de Graff generators make hair stand on end
A rubber belt moves round plastic rollers underneath a metal dome
This causes a buildup of electrostatic charge
If you stand on an insulated chair and put your hands on the dome, electrons will move between your body and the dome
This gives your body a charge
The charge will spread out as much as possible and the like charges repel, the charges are strong enough to make your hairs repel each other causing them to stand on it
