The document discusses the working of several electronic devices:
Remote controls use infrared waves to send commands to devices like TVs. Calculators perform calculations using binary numbers represented as zeros and ones and transistors to solve problems quickly. Digital cameras convert images to digital files by focusing light onto a light-sensitive semiconductor chip that records images as grids of pixels. Radios transmit sound waves as radio signals through antennas that travel through the air. Electric fans use an electric motor to spin fan blades that move air and create a feeling of coolness.