Two identical resistors of resistance R = 24 Ω and a variable resistor R_x are connected to an ideal battery of voltage V as shown in the figure. What should be the value of the variable resistance R_x to make the voltage across the two parallel resistors equal to . A) 4.0 Ω B) 24 Ω C) 8.0 Ω D) 16 Ω E) 40 Ω

Question

Quizplus · Accepted Answer

Using the voltage divider formula, we have: V = (R/(R+R_x))*V and (R_x/(R+R_x))*V Since the two parallel resistors have the same voltage, we set their expressions equal to each other and solve for R_x: (R_x/(R+R_x))*V = (R/(R+R_x))*V R_x = R = 24 Ω Therefore, Choice C is the correct answer.

Two Identical Resistors of Resistance R = 24 Ω and a Variable