Hi everyone, welcome to another #steemitschool blog. Today we will be learning about static electricity and electric fields. I hope you find this blog useful.
Static electricity is a,friction caused, electrical charge that accumulates on the surface of an insulating material.
The charge that has gathered is not able to flow. This means that it cannot easily move away from the insulator.
An example of this is an acetate/polythene rod being rubbed against a cloth duster.
Another example of how static electricity works is the rubbing of a balloon on a jumper. It sticks to the wall!
Credit: http://aplusphysics.com/community/index.php?/blogs/entry/1117-static-electricity/
When the balloon is moved across the jumper, electrons are passed on to the balloon from the jumper. A balloon is then able to stick to a wall. This is because the electrons in the wall repel from the electrons in the balloon, which leaves the surface of the wall positively charge. This then results in the negative charge on the balloon attracting the positive charge on the wall.
Important note: Only electrons have the ability to move. Positive charges will not move.
When there is lots of static electricity built up in one area, it often ends with a spark/a shock as the electrons move again. This occurs as when the voltage (potential difference) gets big enough, the electrons hop across the space between the object that's charged and the earth. This is what the spark is!
Opposite charges = attraction (positive and negative)
Similar charges = repel (Positive + positive or negative + negative)
Credit: https://physics.stackexchange.com)
An objects electrical field can be demonstrated through field lines. The arrows that you will see on the field lines indicates the way in which particles that are positively charged will flow.
Knowing this, it's easy to understand that electrons (negatively charged particles) move in the completely opposite direction to which the arrow is facing.
Important rules with electric fields
When there is a high voltage (potential difference), a powerful electric field is held between the charged object and the one that is earthed.
This powerful electric field results in the electrons (within the air particles) to be taken away. This process is known as ionisation.
Although air is usually an insulator, when it is ionised, it makes it a lot more conductive. This allows the current to flow through it. This is when the spark happens!
The information present in this blog has been mainly sourced from an AQA physics text book and class notes.
Thanks for reading. I hope you learnt something new from this blog.
Hope everyone's having a great week.
Jonathan.
