Diagnosing a parallel circuit: A sudden increase in the total input current to a parallel network most likely indicates which change?

Introduction / Context:
Troubleshooting parallel circuits requires understanding how source voltage and branch resistances affect total current. This item tests your qualitative reasoning about circuit behavior without heavy computation.

Given Data / Assumptions:

• Total current into a parallel network increases suddenly.
• No explicit component values are provided.
• Assume conventional resistive branches and steady-state conditions.

Concept / Approach:
In a parallel circuit, I_total = V_source / R_eq. Therefore, an increase in I_total can be caused by either higher V_source or lower R_eq (e.g., a shorted branch). Conversely, opening a branch increases R_eq and reduces I_total; lowering V_source also reduces I_total.

Step-by-Step Reasoning:

Verification / Alternative check:
If a shorted branch were present (not an answer choice), R_eq would fall dramatically and current would rise as well; however, among the given choices, the correct driver is higher source voltage.

Why Other Options Are Wrong:

• A drop in source voltage: Would reduce current.
• An open resistor: Raises R_eq and reduces current.
• Either of those: Both predict a decrease, not an increase.

Common Pitfalls:

• Confusing series and parallel behavior with component failures.

Final Answer:
an increase in source voltage