In the circuit shown in the figure, the resistor R has a variable resistance. As R is decreased, what happens to the currents? A) I₁ remains unchanged and I₂ increases. B) I₁ decreases and I₂ decreases. C) I₁ decreases and I₂ increases. D) I₁ increases and I₂ decreases. E) I₁ increases and I₂ increases.

Question

Quizplus · Accepted Answer

As R is decreased, the overall resistance of the circuit decreases, which leads to an increase in the total current, IT. According to Kirchhoff's Law, IT is divided into two branches through the junction. Since the resistance in R1 is fixed, the increase in IT is mainly drawn towards the variable resistor R. Therefore, the current in the branch containing R decreases while the current in the branch containing R1 increases. Hence, I₁ decreases and I₂ increases.

In the Circuit Shown in the Figure, the Resistor R