Compute conductance: What is the conductance (in siemens) of an 8 Ω resistor, and which option correctly expresses it in millisiemens (mS)?

Introduction / Context:
Conductance is the reciprocal of resistance and is useful for parallel circuit analysis, admittance calculations, and AC analysis in complex form. Converting between ohms and siemens is a simple but common task in circuit design and troubleshooting.

Given Data / Assumptions:

• Resistance R = 8 Ω.
• Conductance G is defined as 1 / R.
• 1 siemens (S) = 1000 millisiemens (mS).

Concept / Approach:

Use G = 1 / R for DC conductance. Ensure the final unit presentation is correct and, if required, scale to mS for clarity in typical component value ranges.

Step-by-Step Solution:

Verification / Alternative check:

Check reciprocal: 1 / 0.125 S = 8 Ω, which matches the original resistance, confirming the conversion is correct.

Why Other Options Are Wrong:

12.5 mS corresponds to 80 Ω, not 8 Ω. 12 S corresponds to ≈ 0.083 Ω. 8 mS corresponds to 125 Ω. 0.125 S is numerically correct in siemens but the option asks for millisiemens; the best matching formatted answer is 125 mS.

Common Pitfalls:

Forgetting to multiply by 1000 to convert S to mS; mixing up reciprocal relationships; rounding incorrectly when dealing with fractional siemens values.

Final Answer:

125 mS