Values of this property diverge near absolute zero, the first observed example of asymptotic freedom. The von Klitzing constant is written in the units of this property, which can be measured very precisely because of the quantum Hall effect. Three known quantities of it can be used to measure an unknown fourth in the Wheatstone bridge circuit.  Its generalized complex form, which includes an imaginary reactance term, is called impedance. It equals voltage over current. For 10 points, name this 
Values of this property diverge near absolute zero, the first observed example of asymptotic freedom. The von Klitzing constant is written in the units of this property, which can be measured very precisely because of the quantum Hall effect. Three known quantities of it can be used to measure an unknown fourth in the Wheatstone bridge circuit.  Its generalized complex form, which includes an imaginary reactance term, is called impedance. It equals voltage over current. For 10 points, name this property, measured in ohms, the opposition to the flow of electricity.
Values of this property diverge near absolute zero, the first observed example of asymptotic freedom.
electrical resistance