Experimentally how we can measure the power factor of flouroscent tube , Please give the circuit also .?

Answer 1

The basic idea is to measure the voltage across the tube along with the current through the tube, measure the phase angle between them and calculate the cosine of that angle.

In reality, a flourescent tube is very close to a resistive component and any inductive component will be coming from the ballast. I believe that HP used to make a fairly sensitive phase meter for taking such measurements, but I haven't seen one of them in years.

Doug