Question

Consider the circuit shown (https://imgur.com/a/w76kvp6)

R1 = 18 Ohms P1 = 72 W

R2 = 24 Ohms

R3 = 12 Ohms

R4 = 22 Ohms P4 = 88 W

Consider creating a VIRP table to help organize your information.

A) What is the value of the voltage source?

B) What is the current flowing through R3?

Answer 1

Find the current in R1, which is the common current:

$$I=\sqrt{P_1/R_1}=2\text A.$$

The value of the voltage source:

$$V=IR_1+IR_4+I\frac{R_2R_3}{R_2+R_3}=96\text V.$$

The voltage in R3 and R4 is the same:

$$V_3=V_4=I\frac{R_2R_3}{R_2+R_3}.$$

The current flowing through R3 is

$$I_3=\frac{V_3}{R_3}=I\frac{R_2}{R_2+R_3}=1.33\text{A}.$$