Resistor circuit symbols. The unit or resistance is the Ohm, Ω and resistor values may be seen quoted in terms of Ohms - Ω, thousands of Ohms or kilohms - kΩ and millions of Ohms, megohms, MΩ. When written on circuits values like 10k may be seen meaning 10 kilohm, or 10 kΩ. The Omega sign is often omitted and the decimal point replaced by ...