Does technology always follow science? Explain.

Always is a pretty absolute word and since nothing is impossible I would say no. However, usually for the most part technology does follow science.

If you want to develop a technology, you need to understand the physical principals behind it such as dynamics, material behavior, etc. this all requires knowledge physics and chemistry.

Physicists during the 1800's were studying the theory to magnetic and electric fields and their interactions way before they were devices to create/observe this phenomenon esp. according to their theory.