For R2:

P2 = I2 x R1

P = (4 amps)2 x 10 Ohms

P2 = 160 watts

For R3:

P3 = I2 x R3

P = (4 amps)2 x 15 Ohms

P3 = 240 watts

To obtain total power:

PT = P1 + P2 + P3

PT = 80 watts + 160 watts + 240 watts

PT = 480 watts

To check the

answer,

the

total

power

delivered

by

the

source

can

be

calculated:

Psource = Tsource x Esource

Psource = 4 amps x 120 volts

Psource = 480 watts

The total power is equal to the sum of the power used by the individual

resistors.

b. *Summary of Characteristics.*

The important factors governing the

operation of a series circuit are as listed below. These factors have been

set up as a group of rules so that they may be easily studied. These rules

must be completely understood before the study of more advanced circuit

theory is undertaken.

(1) *Rules for Series DC Circuits.*

(a) The same current flows through each part of a series circuit.

(b) The total resistance of a series circuit is equal to the sum

of the individual resistances.