True/False: magnetic loading and teeth flux density

FALSE.

The teeth carry the gap flux through an iron area smaller than the gap area (tooth width is less than slot pitch). Tooth flux density is roughly

$$B_t \approx B_g \times \frac{\text{slot pitch}}{\text{tooth width} \times k_i}$$

So a higher specific magnetic loading (higher $B_{av}$, hence higher $B_g$) raises the flux density in the teeth. This is why $B_{av}$ is limited: tooth density should not exceed about 2.1–2.2 Wb/m², otherwise the teeth saturate and a large field mmf is needed.

Example: with $B_g = 0.8$ Wb/m², slot pitch 30 mm, tooth width 15 mm and $k_i = 0.9$, $B_t \approx 0.8 \times 30/(15 \times 0.9) = 1.78$ Wb/m²; raising $B_g$ to 1.0 Wb/m² gives $B_t \approx 2.22$ Wb/m², which is already at the saturation limit.