Static Electricity Flashcards
What allows and electric charge to pass through it and what does not?
Good conductors allow an electric charge to pass through them whereas insulators do not.
If a substance gains electrons what does it become?
It becomes negatively charged.
If a substance loses electrons what does it become?
It becomes positively charged.
When a charged object comes near to another object they will either attract or repel each other. Explain this.
If the charges are the same - they repel.
If the charges are opposite - they attract.
If one is charged and the other is not - they attract.
How can someone get an electrostatic shock?
You can get an electrostatic shock if you are electrically ‘charged’ and you touch something that is earthed or if you’re earthed and you touch something that is charged.
How can you tell if an object is charged?
If a plastic rod is rubbed with a duster, it attracts small pieces of paper
When a balloon is rubbed against a jumper it can stick to a wall. Some dusters are designed to become charged so that they attract dust.
What are some of the problems with static?
Dust and dirt are attracted to insulators such as TV screens and computer monitors.
Clothes made from synthetic materials cling to each other and to the body, especially just after they’ve been in a tumble drier.
When can static become dangerous?
There are inflammable gases or vapours or a high concentration of oxygen. A spark could ignite the gases and cause an explosion.
You touch something with a large electric charge on it. The charge will flow through your body causing an electric shock. This could cause burns or even stop your heart. A person could die from an electric shock.
How can you reduce your chances of getting an electric shock?
An object that might become charged is connected to the Earth by an earth wire, so any charge immediately flows down the earth wire.
In a factory, machinery operators stand on insulating mats or wear shoes with insulating soles. This stops any charge flowing through them to the Earth.
Lorries containing inflammable gases, liquids and powders are connected to the Earth by an earth wire before being unloaded. This means charge immediately flows down the earth wire preventing a spark that could cause an explosion.
When an aircraft is refuelled, static can build up. This could cause sparks, which could ignite the fuel. A bonding line is used to earth the aircraft before it is refuelled.
What are the uses of static electricity?
Photocopiers, laser printers, defibrillators, electrostatic dust precipitators, paint spraying, insecticide sprays.
