4. Can you explain what energy these electrical appliances in question 3 convert into?

Heat energy, light energy. The device that consumes electrical energy in the circuit is called an electrical appliance (also called a load). It is a device that uses electrical energy to perform work. Such as lights, televisions or resistors and other electrical appliances. Incandescent lamps are electric light sources that energize and heat the filament to an incandescent state and use thermal radiation to emit visible light. Most of the electrical energy is converted into useless heat energy, and only a small part of the energy is converted into light energy. Energy, referred to as "energy", is a measure of the degree to which the spatiotemporal distribution of mass may change, and is used to represent the ability of a physical system to do work.