Parallel RC fundamentals — convert impedance to admittance: If the equivalent impedance magnitude of a parallel RC circuit is given as 2 kΩ, what is the corresponding admittance magnitude?

Introduction / Context:
Admittance is the reciprocal of impedance and is a convenient way to analyze parallel AC networks. While impedance Z is measured in ohms, admittance Y is measured in siemens. For magnitude-only questions, the conversion is straightforward when a single impedance magnitude is specified.

Given Data / Assumptions:

• Equivalent impedance magnitude Z = 2 kΩ (i.e., 2000 Ω).
• We need the admittance magnitude Y = 1 / |Z|.
• The question asks only for magnitude, not phase or rectangular components.

Concept / Approach:
For magnitude-only conversion, use Y = 1 / Z. Units invert from ohms to siemens. For example, 1 / 1000 Ω = 1 mS. Keeping track of prefixes avoids rounding errors and reinforces comfort with engineering notation.

Step-by-Step Solution:

Verification / Alternative check:
Use kΩ to mS reciprocal pairing: 1 kΩ ↔ 1 mS. Therefore, 2 kΩ ↔ 0.5 mS = 500 µS. Both methods agree.

Why Other Options Are Wrong:
2 kS and 4 kS are far too large (they would correspond to 0.5 mΩ and 0.25 mΩ, respectively). “More information is required” is not true when only magnitude is requested. 50 µS corresponds to 20 kΩ, not 2 kΩ.

Common Pitfalls:
Confusing siemens with microsiemens, or reciprocating the numeric value without converting units properly (kΩ ↔ mS).

Final Answer:
500 µS