Circuit elements - Parallel and Series Flashcards
How can you identify elements that are in a series?
Circuit elements are said to be connected in series if all of the elements carry the same current.
How can you find the total resistance in a series?
Sum of all resistance.
RT = R1 + R2 + R3 + …..
True or false.
The total resistance in a series is always bigger than any one resistor in that series?
TRUE.
The total resistance is always bigger.
Define voltage division
Divifing the voltage so that the voltage drop across one resistor is a proportion/percentage of the overall drop.
What is the equation used for voltage division?
Vx = Rx / RT * Vs
The voltage drop across one resistor is equal to the resistance of that resistor divided by the total resistance, all multipied by the voltage source.
How can you identify parallel connected elements?
They have the same voltage across their terminals.
Circuit elements are said to be connected in parallel if all of the elements share the same pair of
nodes
In parallel elements, the voltage is the same for all elements. Is the current also the same for each element?
Nope.
The current is divided amongst the branches.
When dealing with parallel elements, can the equivalent resistance be smaller than the smallest resistor?
Yes.
The equivalent resistance of parrallel elements is ALWAYS smaller than the smallest resistor.
What is the equation for current division?
ix = RT / Rx * i
The current across element x is the total resistance divided by the resistance x, all mutiplied by the total current.
Note that this is the inverse of voltage division.
What is the equation to determine equivalent resistance of elements in parallel?
Req = ____1_____
1/R1 + 1/R2 + 1/R3 + …
OR
1/Req = 1/R1 + 1/R2 + 1/R3 + …
If there are only 2 elements in parallel, what equation can be used to find the equivalent resistance?
Req = R1R2 / R1+R2
= Product / Sum
What is the equation for voltage division?
Rx / RT * Vs
What is the equation for current division?
RT / Rx * is
