DC Circuits Flashcards
What does a DC need? What happens if it doesn’t have it?
A battery and device to consume the energy
The system would be short circuited
What does a resistor look like in the US and in the UK?
UK = the resistor I know
US = squigly line
What are we often asked for when a circuit has mixture of componants?
The valuev
What does calculating the value of resistors require?
Two different approaches for parrellel and series circuit
What is the value shortened to?
RvT (resistance total)
What is the RvT with a series circuit with two 5 ohm resistors?
Rvt = 5Ω+ 5Ω= 10Ω
What does not matter when calculating total resistance in a series curcuit?
The amount of resistors, you always add them up
How do we calculate the value when we have two resistors in a parallel curcuit?
Rvt = (1/5+1/5)^-1 = 5/2 = 2.5Ω
How do we calculate the value if we have two in a series then a single resistor in parrallel?
The two in series are 5Ω and 2Ω and the parrallel one is 100Ω
Rvt = (1/7+1/100)^-1= 700/107= 6.54Ω
Give the equation for current
Current = voltage/resistance
I = V/R
The voltage is 8V and the value is 125Ω, what is the current?
I = V/R
I = 8/ 100 +25 = 0.064A
O.064A moves around a circuit with 8V. What does this mean? (2)
That the battery uses 8V of electrical energy to push 0.064 amps of current around.
0.064A leaves then reenters the battery after it’s completed circuit
What has to be fully consumed in a series?
The voltage
How do we calculate the voltage used by a resistor? 25ohm and 100ohm. Current is 0.064
25ohm
V = IR
V = 0.064 x 25
V = 1.6V
100ohm
V = 0.064 x 100
V = 6.4
What is always true in a circuit (2)
The current out the battery is equal the total current returning to the battery
The total voltage drop across each resistor is equal to the total voltage output of the battery
