| Ohms
Law - |
|
| In a D.C.
circuit the current is directly proportional to the applied voltage
and inversely proportional to the resistance. |
Current
(A) = I
Voltage (V) = V
Resistance = R |
| |
|
|
| Kirchoff's
Laws |
|
|
| 1st.
Law |
|
| At any electrical
junction the current flowing into the junction is equal to the
sum of currents flowing out of the junction. |
| |
| Therefore
I1 = I2 + I3 + I4 |
| |
| |
| 2nd
Law |
|
| The sum
of the voltage drop across any complete path of components connected
across the voltage supply equals the voltage provided by the power
supply. |
|
| |
| Therefore
V4 = V1 + V2 +V3 |
| |
| |
|
|
| Component
Layout |
|
|
| Series |
|
|
If two
components are connected in series and they each have the same
resistance the voltage flowing through component is the same (half
of the supply voltage)
|
|
| Therefore
V1 = V2 + V3 |
|
| and the
current flowing through each lamp is the same. This is shown in
figure 1. |
|
| Parallel |
|
|
| When two
components are connected in parallel the voltage appears across
both components |
|
|
| |
|
| Therefore
V1 = V2 = V3 |
|
| |
| The current
flowing across the two components are equal but half of the current
from the power supply so I1 + I2 = IT. This is shown in Figure
2 |
| |
| Therefore
I1 = I2 +I3 |
| |
|
|
