To put it simply, it is mainly because all conductors are cut, and each section of conductor is regarded as a short section of conductor, so induced electromotive force is generated. However, because all conductors are closed, the whole conductor has no electromotive force and will not generate current.

In a uniform magnetic field, some conductors are cut, so it is impossible to talk about magnetic flux, because magnetic flux must have an effective area when it passes through the magnetic field, while in a uniform magnetic field, some cuts only produce induced electromotive force, so it cannot form current.

Sorry, that's all I can say. The landlord can go to the local bookstore to find reference materials.