If a toroid uses bismuth for its core, will the field in the core be greater or less than when the core is empty?

Question

If a toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?

Answer 1

: It is known that Bismuth is a diamagnetic substance. This means, the magnetic field due to the toroid will be the magnetizing field for the bismuth core which will be opposite to the induced magnetic field of Bismuth. Hence the total field generated by the toroid will be slightly less than the empty-core-toroid.