What does the minus sign in the formula for the law of electromagnetic induction show?

The minus sign shows that the induction EMF causes an induction current in such a direction that the magnetic flux created by it is directed against the change in the magnetic flux (trying to compensate for it), causing the induction current.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.