Resistance Converter

Convert between different units of electrical resistance measurement including ohms, kilohms, megohms, abohms, statohms, and more. Essential for electrical engineering and electronics applications.

Common Resistance Conversions

SI Prefixes:
• 1 kΩ = 1,000 Ω
• 1 MΩ = 1,000,000 Ω
• 1 mΩ = 0.001 Ω
• 1 μΩ = 0.000001 Ω
Standard Values:
• Resistors: 1Ω to 10MΩ common
• Wire: mΩ to Ω range
• Insulators: MΩ to GΩ range
• Semiconductors: Variable range
Typical Examples:
• Copper wire: ~17 μΩ⋅m
• LED current limiting: 220Ω
• Pull-up resistor: 10kΩ
• Multimeter probe: 10MΩ
Special Units:
• 1 abΩ = 10⁻⁹ Ω (CGS EMU)
• 1 statΩ ≈ 8.99 × 10¹¹ Ω (ESU)
• RK ≈ 25,813 Ω (quantum resistance)
• 1 Ω = 1 V/A

⚡ Resistance Fundamentals

Definition: Opposition to electric current flow (Ω = V/A)

Conductance: Reciprocal of resistance (G = 1/R, measured in Siemens)

Temperature Effect: Most materials' resistance changes with temperature

AC vs DC: Impedance (Z) includes reactance for AC circuits

Power Dissipation: P = I²R = V²/R (Joule heating)

🔬 Resistance by Application

• nΩ-μΩ: Superconductors, contact resistance
• mΩ-Ω: Power circuits, current sensing
• Ω-kΩ: General electronics, current limiting
• kΩ-MΩ: Signal processing, biasing
• MΩ-GΩ: High impedance, insulation
• TΩ+: Ultra-high impedance, electrometers

🎯 Resistor Color Codes & Standards

Standard Values: E12 series (10%, 12 values/decade), E24 series (5%)

Power Ratings: 1/4W, 1/2W, 1W, 2W common for through-hole

Tolerance: ±1%, ±5%, ±10% typical for general purpose

Temperature Coefficient: Usually specified in ppm/°C

🧮 Key Formulas & Relationships

Ohm's Law: R = V/I

Series: R_total = R₁ + R₂ + R₃ + ...

Parallel: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃ + ...

Power: P = V²/R = I²R

Resistivity: R = ρL/A (ρ = resistivity, L = length, A = area)

🔬 Quantum & Special Resistances

Quantum Resistance: RK = h/e² ≈ 25,812.807 Ω

Hall Effect: Used in quantum Hall effect measurements

Josephson Junction: Zero resistance in superconductors

Planck Impedance: √(μ₀/ε₀) ≈ 376.7 Ω (impedance of free space)

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