Electricity Flashcards
Conductor
An object that can conduct or allow an electric current to flow through it.
Insulator
An object which doesn’t allow an electrical current to flow through it
Structure of the atom
Nucleus = protons (positive charge) + neutrons (no charge) do not move
Shell = electrons (negative charge) rotate in shells around nucleus
What is the law of electrostatics?
Like charges repel, opposite charges attract
What would happen if two positively charged objects came near each other?
The objects would repel from each other as like charges repel.
What would happen if a positively charged object and negatively charged one came near each other?
They would attract as opposite charges attract.
What would happen if two negatively charged objects came near each other?
They would repel as similar charges repel.
What happens when you rub two neutrally charged objects together (charge by friction)?
When you rub two neutrally charged objects together, electrons are either transferred or received. One of the object will lose electrons and the other will take those electrons. This results in one positively charged object as there are now more protons than electrons in the atoms, and one negatively object as there are now more electrons than protons in the atoms.
How do objects get charged?
By the transfer of electrons, the only subatomic particle that can move in and out of the atom.
What charge do acetate rods always become when charged by friction? Why?
Positive, electrons are transferred from rod to cloth.
What charge do polythene rods always become when charged by friction? Why?
Negative, electrons are transferred from cloth to rod.
Explain how smoke is filtered
A positively charged grid at the bottom allows the smoke particles to pass through it become positively charged. As the particles and grate are positively charged, they repel away from each other, as like charges repel. As opposite charges attract, the positively charged smoke particles are attracted to the negatively charged plates on either sides of the filter, and the smoke is removed from the air.
What charges do the car and the paint have when spray painting cars? Why is this achieve an even mist?
The each drop of paint has negative charge. As like charges repel, the droplets repel from each other into smaller ones. Because, opposite charges attract, the smaller drops of paint are attracted to the car, which has a positive charge, and sticks evenly to the surface.
How does the gold leaf electroscope work?
The top metal plate and gold leaf start neurally charged, but when the negatively charged polythene rod comes near it, the electrons are repelled from it and go down the rod as like charges repel. The electrons leave the electroscope via an earthing wire, leaving the electroscope positively charged and the wire and rod are removed.
Why does a balloon stick to wall after rubbed by a jumper
Balloon gains electrons from jumper and becomes negatively charged. When brought close to the wall, the electrons are repelled away from the ballon as like charges repel. As opposite charges attract, the ballon sticks to the wall , as the protons in the wall are attracted to electrons in the balloon.
