Chapter 22 Flashcards
what is a current
it is the motion of a charge through a conductor
when we connect a charged parallel plate capacitor to a conducting wire, what happens to the net charge od the plates and why
the plates are discharged as the charges flow through the wire in a current
what are charge carriers
charges that move in a current
what are conduction electrons
they are electrons that move around in a metal and create a current
why can an insulator not have a current
no, the elecrons do not flow easily
describe the motion of electrons in a current of a metal
an electric field within the metal exerts a force on the electrons that causes them to accelerate.
these electrons collide into eachother, and kinetic energy is lost as thermal energy which makes the metal warmer
what direction do electrons move in an electric field?
they move opposite of the electric field
when there is a potential difference what happens to the electric field and the current in a wire
the potential difference causes an electric field that points from high potential to low. This drives a current that flows from high to low
if a conductor has a current, why is it not at equilibrium
the charges are in motion
what is the law of conersevation of current
the current is the same at all points in a current-carrying wire.
on either side of a bulb, what is the relationship of the current going into the bulb vs out
it is the same and it is conserved
what direction does current flow?
it flows in the direction of positive charge
What is another way to describe current
it is the rate (C/s) at which charges move through a wire
what is the unit of current
it is 1 ampere= 1A= 1 coulomb per second
what is a junction? what happens to the current of a wire when a junction is present
a junction is where a wire spilts or merges into one. The sum of the current in is the same as the sum of the current out
what do batteries do for.a current
they keep the charges in motion through energy conversions
how does a charge escalator work in a battery
due to chemical reactions, the charges are moved from the low-potential negative terminal and “lifted” to the high-potential positive terminal
what does the charge escalator do for a current
it sustains the current by continuously providing a renewed supply of charges at the positive terminal
What happens in a battery when the charge reaches the positive terminal?
it flows downhill from high potential to low potential and the potential energy is converted to kinetic energy as the charge flows downhill back into the battery in a complete circuit
what is emf or ε
the potential difference created in a battery
what happens to the potential difference when we connect a battery in a series
the potential difference is the sum of the individual batteries differences
what in a battery creates a potential difference
the removal of a charge from the negative to the positive terminal
what is a consequence of a battery’s potential difference
the current
what is resistance
it is how hard it is to push charges through a wire
