3.2 Static Electricity Flashcards
Static electricity is the result of?
Imbalance between negative and positive charges
What are the causes of static electricity?
friction, pressure and separation, this process is called the tribo electric effect
What effects a static charges magnitude?
material composition, applied forces, separation rate and relative humidity.
Materials high on the tribo chart =? and lower =?
Positively charged (lose electrons), lower = negatively charged (gain electrons)
Coulombs law states?
Charged bodies attract or repel each other with a force that is directly proportional to the product of their individual charges, and is inversely proportional to the square of the distance between them.
The amount of attracting or repelling force which acts between 2 static bodies depends on 2 things?
Their charges and the distance between them.
What is the symbol for Coulombs?
C
What is the symbol for charge?
Q
What does 1 Coulomb =
1C = 6.25 x 10 to the power of 18 electrons
What does coulombs measure?
quantity of electric charge
What is conduction current?
The movements at speed of light of the electrons jumping from one atom to the other atom to reach the end of the conductor.
How are electrons conducted in a solid
Via movement of electrons.
How are electrons conducted in a liquid.
It depends on the liquids ability to form ions (positive or negative charged atoms), positive and negatively formed ions will attract to the opposites of the polarity electrodes..
Conductivity of liquids
Liquids which are able to conduct ionically are known as electrolytes
Most electrolytes are?
Acid, Alkali or Salt solutions.
How are electrons conducted into gas?
Heat or high electrical potentials can dislodge electrons or cause them to move into the atoms of a gas, ionising the gas, With the gas ionised conduction current can pass.
Explain thermionic emission
When heating a conductor to a high enough temperature the free electrons will boil off the surface of the conductor. called thermionic emission.
How is electron current created in a vacuum?
By heating the cathode via thermionic emission which forces the electrons off the surface which then the electrons are attracted across to the anode via electrostatic attraction.
