Four resistors are connected across an ideal dc battery with voltage V as shown in the figure.Assume that all quantities shown are accurate to two significant figures.If the total current through this circuit is I = 2.0 A,what is the current through the 4.0-Ω resistor?
A)1.0 A
B)2.0 A
C)3.0 A
D)1.3 A
E)2.4 A

Question

Four resistors are connected across an ideal dc battery with voltage V as shown in the figure.Assume that all quantities shown are accurate to two significant figures.If the total current through this circuit is I = 2.0 A,what is the current through the 4.0-Ω resistor? 
A)1.0 A 
B)2.0 A 
C)3.0 A 
D)1.3 A 
E)2.4 A

Quizplus · Accepted Answer

We can use Ohm's Law to find the voltage drop across the 4.0-Ω resistor:

V = IR = (2.0 A)(4.0 Ω) = 8.0 V

Then, we can use Ohm's Law again to find the current through the 4.0-Ω resistor:

I = V/R = (8.0 V)/(4.0 Ω) = 2.0 A

Therefore, the current through the 4.0-Ω resistor is 2.0 A, which corresponds to choice B.

Four Resistors Are Connected Across an Ideal Dc Battery with Voltage