This is the same as in (a); therefore, the ratio remains unchanged for any value of μ. However, if μ is low, the flux will
tend to leak, invalidating the assumptions used to obtain Eqs. (10.45) and (10.46). If this happens, Eqs. (10.55)
and (10.56) must be used. In practical design, if μ is large (but finite), it is safe to use the assumptions for the ideal
transformer.