What is electrical energy caused by?

Electrical energy is caused by the movement of electrons. In conductive materials, such as metals, electrons can move freely. When an electric field is applied, these electrons are set into motion, creating an electric current. This flow of electrons is what constitutes electrical energy, which can then be harnessed to power devices, appliances, and systems.

Understanding electrical energy as a movement of electrons clarifies how electricity works in practical applications, such as circuits and electronic devices. The other options—magnetic fields, sound wave oscillation, and thermal motion—relate to different physical phenomena that, while important in their respective contexts, do not directly involve the generation or flow of electrical energy. For instance, magnetic fields can influence electric currents but do not generate electrical energy themselves. Sound are vibrations transmitted through a medium and do not involve electron movement in the context of electrical energy. Thermal motion of particles refers to the energy associated with the temperature of a substance, which is not the same as electrical energy generated by electron movement.