Question

The number of conductors on each pole piece required in a compensating winding for a 6-pole lap wound dc armature containing 286 conductors, will be (The compensating winding carries full armature current. Assume ratio of pole arc/pole pitch = 0.7)

• A. 6
• B. 5
• C. 8
• D. 10

Answer 1

The correct option is A 6

$$\begin{array}{cc}A{T}_{cw/pole}& =\frac{I_{0}Z}{2A}\left(\frac{\text{Pole arc}}{\text{Pole pitch}}\right)\\ \therefore N_{cw/pole}& =\frac{Z}{2AP}\left(\frac{\text{Pole arc}}{\text{Pole pitch}}\right)=\frac{286}{2\times 6\times 6}\times 0.7=2.78\end{array}$$
$\text{Compensating conductor/pole}$

$=2.78\times 2=5.56=6\text{(nearest integer)}$