Series and Parallel circuits handout
H)
Series and Parallel circuits
1)
Series circuit - circuit that has only one current path
Reference Table Equations
a)
I T = I 1 = I 2 = I 3 =
This
equation means the total current coming from the source equals the current
going through each resistor.
b)
R T = R 1 + R 2
+ R 3 +
So
R T = __________
This
equation means the total resistance equals the sum of the individual
resistances
c)
V T = V 1 + V 2
+ V 3 +
d)
V T = I T R T
Find
the total current (I T)
Answer
: 3.33
amps
2) Parallel Circuit - circuit in which each component has its own circular path
a)
I T = I 1 + I 2 + I 3 +
For example If
I 1 = 2 amps,
I 2 = 3 amps I 3
= 4 amps
Then
. I T
= _______amps
b)
The voltage drops across each component in parallel is equal
V T
= V 1 = V 2 = V 3
*** Write in the correct voltages in the picture
above
c)
V1 = I1R1 V2 = I2 R2 V3 = I3 R3 etc
*** Use the above
equations to find the current going through the first and second resistor
I1
= __________
I2
= __________
****If the total
current in this circuit is 18 amps,
what is the current going through the last resistor?
****Whats R3 ? _______________
Finding
Total Resistance in a Parallel Circuit
Deriving
an Equation for Total Resistance
Since IT = I1 + I2 + I3 + I4 +
Then
On Reference Table
RT - total Resistance is also called
·
equivalent Resistance
·
combined Resistance
·
Effective Resistance
Find the total Resistance for three resistors of 2 ohms, 5
ohms and 2 ohms connected in parallel.
1=
1 + 1 + 1 1.
Substitute
RT R1 R2
R 3
2. Find
common denominator and solve