Question

A 6 pole, wave connected DC armature has 250 conductors and runs at 1200 rpm. The emf generated is 600V. The useful Flux/pole is:
1. 0.04 Wb
2. 0.4 Wb
3. 4.0 Wb
4. 0.44 Wb

Answer 1

Correct Answer - Option 1 : 0.04 Wb

Concept:

The emf equation for a DC generator is given as

\(E = \frac{{ϕ ZNP}}{{60A}}\) .........(1)

ϕ = flux per pole in weber

Z = number of conductors

N = speed of the rotor

P = number of poles

A = number of parallel paths.

Calculation:

Given

E = 600 V, Z = 250, N = 1200 rpm, P = 6.

For wave winding A = 2

From equation(1)

\(ϕ = \frac{{60EA}}{{ZNP}}\)

\(ϕ = \frac{{60 \times 600 \times 2}}{{250 \times 1200 \times 6}}\)

ϕ = 0.04 Wb