FIGURE 26-20
-A 4.0-Ω resistor is connected in parallel with a 12-Ω resistor and both of these are connected to a DC power supply with voltage V as shown in Fig. 26-20. If the total current in this circuit is 2.0 A, what is the current through the 4.0-Ω resistor?
A)2.0 A
B)2.5 A
C)0.5 A
D)3.0 A
E)1.5 A

Question

FIGURE 26-20 
-A 4.0-Ω resistor is connected in parallel with a 12-Ω resistor and both of these are connected to a DC power supply with voltage V as shown in Fig. 26-20. If the total current in this circuit is 2.0 A, what is the current through the 4.0-Ω resistor?
A)2.0 A 
B)2.5 A 
C)0.5 A 
D)3.0 A 
E)1.5 A

Quizplus · Accepted Answer

The total resistance in parallel is given by 1/R_total = 1/R1 + 1/R2. For R1 = 4Ω and R2 = 12Ω, R_total = 3Ω. Using Ohm's law (V = IR), V = 2A * 3Ω = 6V. The current through the 4Ω resistor is V/R1 = 6V/4Ω = 1.5A.

FIGURE 26-20 -A 4.0-Ω Resistor Is Connected in Parallel with a 12-Ω