Chpt 16: Electric Charge and Fields Flashcards
what is charge?
the property by which a body can attract or repel another body without directly touching it
What is the primary carrier of ‘charge’?
electrons
what is the main idea of conservation of charge?
it cannot be created or destroyed; it has to come from somewhere and go somewhere.
where does an object’s charge go when it isn’t connected to the ‘ground’?
usually it’s absorbed by polar water molecules in the air
which type of object requires ‘contact’ in order to influence charge flow: conductors or inducers?
conductors
which type of object DOES NOT require ‘contact’ in order to influence charge flow: conductors or inducers?
inducers
where does charge flow to in the case of conductors?
from one object to another
where does charge flow to in the case of inducers?
from one region of an object to another region of the same object.
How are semi-conductors different from conductors?
in a semiconductor, electrons move within their respective atoms, but do not more freely throughout the object itself
what is the ‘ground’?
a reservoir for collecting/pooling charge
what is Coloumb’s law the expression for?
The amount of electric force (attraction or repulsion) experienced by one body due to another
what is the eqn for Coloumb’s law?
F = k(Q1Q2/r^2)
what is the charge on one electron?
- 1.6E-19C
what is the sign for the charge on one electron?
-
what is the sign for the charge on one proton?
+
When you plug charges into the Coloumb’s law eqn, do you include their charges or included them as absolute values?
absolute values
What is the K constant value in the coulombs law equation?
9.0E9 (Nm)/C^2
what is the electronic force?
the interaction between electrically charged particles
The attractive or repulsive interaction between any two charged objects
what is the electronic force also called?
electric force
electromagnetic force
How does Dr. Beacom describe ‘static electricity’?
as the transfer of electrons between insulators
a stationary electric charge, typically produced by friction, which causes sparks or crackling or the attraction of dust or hair.
How does Dr. Beacom distinguish between an electric conductor and an electric insulator?
in conductors charge moves freely bc the electrons are not tightly bound to their atoms.
In insulators, charge does NOT move freely bc the electrons ARE tightly bound to their atoms.
is plastic an insulator or conductor?
insulator
is metal an insulator or conductor?
conductor
what is the mass of an electron?
9.10938356 × 10-28 grams
What does Dr. Beacom say is the main thing we’re trying to understand with electric fields?
Trying to understand how forces act at a distance
if electric charges create fields ( that exert interactive forces), what direction does the field point when the charge is positive?
away from the positive charge causing the field
if electric charges create fields ( that exert interactive forces), what direction does the field point when the charge is negative?
towards the negative charge causing the field
are field-causing charges usually drawn as positive charges or negative charges?
usually positive but they can be drawn as negative
