Four resistors are connected across an 8-V DC battery as shown in the figure.The current through the 9-Ω resistor is closest to
A) 1 A.
B) 0.7 A.
C) 0.5 A.
D) 0.9 A.
E) 2 A.

Question

Four resistors are connected across an 8-V DC battery as shown in the figure.The current through the 9-Ω resistor is closest to 
A) 1 A. 
B) 0.7 A. 
C) 0.5 A. 
D) 0.9 A. 
E) 2 A.

Quizplus · Accepted Answer

Using Ohm's Law, we can first find the total resistance of the circuit:

Rtotal = R1 + R2 + R3 + R4 
Rtotal = 6 Ω + 12 Ω + 4 Ω + 9 Ω 
Rtotal = 31 Ω

Next, we can use Ohm's Law again to find the current (I) through the circuit:

I = V / Rtotal 
I = 8 V / 31 Ω 
I ≈ 0.258 A

Finally, we can use Ohm's Law one more time to find the voltage drop (V) across the 9-Ω resistor:

V = IR 
V ≈ 0.258 A × 9 Ω 
V ≈ 2.32 V

Thus, the current through the 9-Ω resistor is closest to:

I = V / R 
I ≈ 2.32 V / 9 Ω 
I ≈ 0.258 A

which is closest to choice letter B (0.7 A).

Four Resistors Are Connected Across an 8-V DC Battery as Shown