On the basis of what law can it be argued that in an oscillatory circuit a change in the energy of an electric field is equal

On the basis of what law can it be argued that in an oscillatory circuit a change in the energy of an electric field is equal to a change in the energy of a magnetic field?

Based on the law of conservation of energy.

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.