Fundamental of Physics

Physics is one of the more fundamental scientific fields, and electrical engineering spans much of it. Electromagnetism is obviously very relevant to electrical engineering, but other parts of physics are also important. Since light is a form of electromagnetism, optics is important not just to lasers and their applications but to optical and radio communications more generally.
Semiconductors (transistors, diodes, integrated circuits, solar cells, etc) all rely on "solid state physics", which in turn relies on quantum physics.
Electrical engineers often need to convert electrical energy to and from other forms of energy, e.g., with motors, generators, lights, solar panels, heaters, sensors and so forth, so an understanding of mechanics and thermodynamics is helpful. Electrical energy is often stored in batteries, so chemistry (itself an offshoot of physics) is also relevant. Even relativity has important engineering applications. Not only is it the modern way to understand electromagnetism, it is an everyday engineering reality in modern satellite navigation systems such as GPS, Glonass and Galileo. In fact, modern satellite engineering is a highly interdisciplinary field that applies just about every aspect of physics plus mathematics, communication theory, computer science and mechanical and aerospace engineering.