Question

What is the common unit of conductivity if the dimensions are expressed in centimeter?

Options

• Ω⁻¹ cm

• Ω cm⁻¹

• Ω⁻¹ cm⁻¹

• Ω cm

Answer 1

Ω⁻¹ cm⁻¹

Explanation:

If ρ is a resistivity and K is conductivity or specific conductance, then

κ = `1/ρ`

∵ ρ = `"R" xx "a"/"l"`

∴ κ = `1/"R" xx "l"/"a"` Ω⁻¹ m⁻¹ or (ohm⁻¹ m⁻¹ or S m⁻¹)

(In the C.G.S. system, the units of κ are Ω⁻¹ cm⁻¹ or S cm⁻¹ which are used commonly)