a strange question

[j.mawer]

Resistance = (resistivity * length)/CSA
= (2.84e-8 * 100)/ 120e-6
= 0.0237

remember that 120mm^2 = 120e-6m^2 because there are 1,000,000 mm2 in a m2 (1000mm *1000mm)

 

[lofty84]

A resistor of 4 ohms and pure inductor with inductive reactance of 3 ohms are connected in series to 200v AC supply. Calculate the current.


square root of 4sq + 3 sq = 5

200 / 5 = 40 A

 

[lofty84]

this is really frustrateing me as I cant work them out

determine the power in a three phase star wired balanced load circuit when the line current is 15a the phase voltage 230 v and the power factor is 0.8

also doing my head in is

a 15kw three phase delta connected balanced load has a power factor 0f 0.85 determin the line current (i think 400 v has been left out of this question somewhere)

please can anyone help

 

[lofty84]

Thanks to everyone who helped me get a credit, nice one

 

[IQ Electrical]

Well done !