Electrostatics Flashcards
Define charge
- One of the basic properties of the elementary particles of matter
- giving rise to all electric and magnetic forces and interaction
Define ELECTROSTATIC charge
- Electric charge at rest
- on the surface of an insulated body
Define electric force field
- the region around a charged particle or object
- in which it exerts a force on another charged particle or object
What is the direction of the electric field (at a point)?
the direction that a positive test charge would move if placed at that point
Define electrostatic force
the force exerted by non-moving (static) charges on each other
What is the Basic Law of Electrical Charge?
- like charges repel each other
- unlike charges attract each other
What is the Law of Conservation of Charge?
- the net charge
- of an isolated system
- remains constant
Q of one electron =
-1,6 x 10^-19
Q of one proton =
+1,6 x 10^-19
no. of particles =
total charge / charge on one particle
total charge =
no. of particles x charge on one particle
charge on one particle =
total charge / no. of particles
Great electron affinity
when atoms of a substance attract some electrons from the other substance to itself
Define triboelectric series
a series that compares abilities of substances to lose of gain electrons by friction
Effects of electrostatic forces can be…
attractive or repulsive
What are the characteristics of an electrostatic force?
- a non-contact or field force
- gets weaker the further apart the charges are
- depends on the strength of the charges
- only occurs when there is an interaction between 2 or more objects
What is an electroscope?
- an instrument that can detect the presence of a charge
What is an electroscope composed of?
- a metal disk
- sphere
- rod
- thin gold leaf
- inside a transparent container
When an electroscope is neutral…
- same number of protons and electrons
- electrons move around
- protons trapped in nuclei
- charges are evenly spread
When there is a negatively charged rod NEAR the disc…
- same number of protons and electrons
- electrons repel and move down conductor to the leaves
- electroscope is polarised
- neutral charge but unevenly spread
- gold leaves have surplus electrons
- they deflect
When there is a positively charged rod NEAR the disc…
- same number of protons and electrons
- electrons in the leaves get attracted to positive charge
- electrons move up the conductor to the disk
- electroscope is polarised
- neutral but unevenly spread
- leaves have an electron deficit
- they deflect
When there is a charged rod TOUCHING the disk…
- electroscope becomes polarised
- some electrons of rod move up or down conductor to leaves
- when rod is removed - electroscope has more or less electrons
- rod lost some charge during contact
Symbol G
Giga, 10^9
Symbol M
Mega, 10^6
Symbol k
Kilo, 10^3
Symbol m
milli, 10^-3
Symbol u
micro, 10^-6
Symbol n
nano, 10^-9
Symbol p
pico(pica), 10^-12
Symbol d
deci, 10^-1
Symbol c
centi, 10^-2
