Context: A watt balance is an instrument for comparing two powers, one of which is measured in SI watts and the other of which is measured in conventional electrical units. From the definition of the conventional watt W90, this gives a measure of the product KJ2RK in SI units, where RK is the von Klitzing constant which appears in the quantum Hall effect. If the theoretical treatments of the Josephson effect and the quantum Hall effect are valid, and in particular assuming that RK = h/e2, the measurement of KJ2RK is a direct determination of the Planck constant.

Question: What is a watt balance?
Answer: an instrument for comparing two powers, one of which is measured in SI watts and the other of which is measured in conventional electrical units

Question: What value does RK represent?
Answer: the von Klitzing constant which appears in the quantum Hall effect

Question: If the effects are valid, for RK = n/e2, what is the measurement of KJ2RK equal to?
Answer: the Planck constant

Question: What does a watt balance avoid?
Answer: Unanswerable

Question: What value does RM represent?
Answer: Unanswerable

Question: What is the measurement of KJ2RR equal to?
Answer: Unanswerable

Question: What gives gives a measure of the product KJ2RR in SI units?
Answer: Unanswerable