circuits Flashcards
(25 cards)
current electricity
the rate of flow of electrons
electrical circuit
path for transmitting electrical current
current
rate at which electrons flow
how do electron flow
electrons flow out of negative into positive terminal
direct vs alternating current
- direct: flow of charge always in same direction
- alternating: direction of charge flow switches back nd forth at regular intervals
resistance
degree to which the flow of electrons is opposed
why are resistors used
to decrease current flow by converting it to heat
which factors impact resistance of a wire?
- thickness
- length
- material
- temperature
how does thickness impact resistance?
- thin: increases resistance
- thick: decrease resistance
how does length impact resistance?
- long: increase
- short: decrease
how does material impact resistance?
- iron/rubber/glass/plastic: increase
- copper/aluminum: decrease
how does temperature impact resistance?
- hot: increase
- cold: decrease
ohms law
- current flowing through circuit is directly proportional to potential differences maintained across its ends (physical conditions kept consistent)
- V=IR
current units
- I in A (amperes)
charge units
- q in C (coulombs)
time units
- t is s (seconds)
resistance units
- R in (ohms)
voltage units
- V in V (volts)
power units
- P in w (watts)
current in series vs parallel
- series: It=I1=I2… (same everywhere)
- parallel: It=I1+I2… (sum of branches)
resistance in series vs parallel
- series: Rt=R1+R2… (sum of all)
- parallel: 1/Rt=1/R1+1/R2… (decrease as branch increase)
series circuit
- current has single path
- current goes through every component
- if one component goes out, circuit is incomplete nd all stops working
parallel circuit
- current has multiple paths
- current goes through each path
- still works if one branch goes out bc circuit is still complete
potential difference
- volts
- work done by a charge as it moves between two points
