Static And Currant Electricity Flashcards
What causes static electricity
When 2 insulation materials are rubbed together, electrons transfer from one material to the other. This causes an electrical charge, electrostatic charge.
Name the relative mass and charge of:
Neutron
Proton
Electron
Neutron rm = 1 charge = 0
Proton rm = 1 charge = 1
Electron rm = 1 charge = -1
Explain the process that makes a negatively charged balloon stick to a wall
This is caused by charging by induction and the charge is an induced charge. When the negative balloon is put by a wall, the electrons in the wall are repelled away leaving a positive charge (induced charge) on the wall. This makes the balloon attract to the wall so they stick together.
How do you lose electrostatic charge
If you build up a charge, those electrons want to get to the Earth. If you touch a conductive material, the electrons will transfer from you to the material to get to the Earth. This process of electrons transferring from you to the earth through a conductor is called earthing. You are now discharged.
What causes lighting and thunder
Static electricity can build up between clouds. This causes huge build up of electrostatic currant. This is then discharged through the atmosphere in a huge spark. This is what lighting is. Sound waves are also produced which makes the thunder
What is a bonding line and why are they important.
They are metal wires used to connect an aircraft to the ground before and during its refuel. As fuel goes from the hose to the aircraft, electrostatic charge can build up which could cause a spark which would ignite the fuel. The bonding line makes sure this doesn’t happen as the charge goes from the aircraft, along the wire and into the earth.
What prevents electrostatic charge when filling tanks at petrol stations
The stations tanks are built into the earth from a conductive material. This means when it is filled by a hose, there is no electrostatic charge as it goes straight into the earth.
How can static electricity be used for painting
The object that needs paining can be connected to a negative terminal to give it a negative charge and the nozzle of the spray can is connected to a positive terminal. This means when the droplets of paint are sprayed, they become positively charged and are attracted to the negatively charged object. When the object has been sprayed, it becomes neutral. This means the paint is spread evenly because once there is paint, the paint is no longer attracted to that part of the object
Why can’t conductive materials be given electrostatic charge but insulators can
If a conductor was given charge, it would be conducted ways and discharged. An insulator can’t conduct meaning the charge stays with the material.
What is currant
The flow of electrons in a conductor
What is the difference between alternating and direct currant and what produces them
Cells and batteries create direct currant meaning the currant only flows in one direction
Generators produce alternating currant meaning the currant changes directions multiple times a second
What is the formula for charge
Charge = currant x time
Q = I x t
E.g. 5A for 10 seconds
5 x 10 = 50C
