Quick question

[hammond]

Hey there, sorry to ask this noobie question, have been doing them all evening and this one I cant but into words, the question asks

Why is the assumed current different to the measured current from a digital/analogue meter.

This is in a single phase circuit section.

I have a general answer just can put it into words

Any help?!?

 

[Tag]

a measured current is more accurate than a assumed measurement?

 

[hammond]

Yes that is right, but surely theres got to be more than that?

 

[Tag]

I'm guessing the assumed current is the design current of the circuit, where as if you measured it with a digital/analogue meter it would be slightly different to the design current (Ib).

 

[hammond]

Any help with this one

Calculate the power factor of a fluorescent luminaire.

Now I know the formula for this, P / VxI (true power divided by voltage and current)

I have the supply voltage, lamp voltage and choke voltage, but am confused on which I use in the formula.