Basic DC Theory
BASIC DC CIRCUIT CALCULATIONS
Figure 21 Example 1 Series Circuit
Solution:
Step 1:
Find circuit current. As we already know, current is the same throughout a series
circuit, which is already given as 0.5 amps.
Step 2:
Find RT.
RT = R1 + R2 + R3
RT = 50 W + 75 W + 100 W
RT = 225 W
Step 3:
Find VT. Use Ohm’s law.
VT = IRT
VT = (0.5 amps)(225 W)
VT = 112.5 volts
Example 2:
A 120 V battery is connected in series with three resistors: 40W, 60W, and 100W
(Figure 22). Find the voltage across each resistor.
Rev. 0
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