Underdetermined value in a labeled network: A resistor R1 is referenced in a circuit, but no component values or node voltages are supplied. What is R1 equal to under these conditions?

Difficulty: Easy

Correct Answer: Cannot be determined from the information provided

Explanation:


Introduction / Context:
Component values cannot be inferred from labels alone. Without measurement data, design constraints, or relationships from the rest of the circuit, a label like “R1” is just an identifier. This question reinforces the need for complete specifications before calculating a numerical value.


Given Data / Assumptions:

  • No diagram or numerical constraints are included.
  • R1 is referenced but not defined by any equations in the stem.
  • Standard passive linear component behavior is assumed.


Concept / Approach:
To solve for an unknown resistance, you typically need Ohm’s law with known voltage and current, a divider/bridge relationship, or network equations (KCL/KVL). Without such information, the value is indeterminate; many different values could satisfy an unspecified circuit.


Step-by-Step Solution:

Look for given voltages/currents: none provided.Look for ratios (e.g., bridge balance): none provided.Conclude the system is underdetermined; R1 cannot be solved numerically.Therefore, select the non-numeric option indicating insufficiency of data.


Verification / Alternative check:
If even a single additional relation were provided (e.g., total current and total voltage in a simple series), you could compute R_total and potentially deduce R1 in combination with other known resistors. The absence of such data confirms the conclusion.


Why Other Options Are Wrong:
Specific numbers (100 kΩ, 200 kΩ, 300 kΩ, 50 kΩ) are arbitrary without supporting data.


Common Pitfalls:
Guessing “typical” values; always demand the equations or measurements that define an unknown.


Final Answer:
Cannot be determined from the information provided

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion