A microscope, in which maximum magnification is achieved, but the object cannot be seen by eye, is called

The electron microscope is the correct answer because it provides the maximum magnification and resolution compared to optical microscopes. While light microscopes (compound, dissecting, and phase contrast) use visible light and lenses to form an image that can be viewed directly by the human eye, electron microscopes use a beam of accelerated electrons. Because the human eye cannot detect electron beams, the resulting image must be projected onto a fluorescent screen or captured by a digital sensor to be visualized. Electron microscopes, such as the Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM), achieve magnifications far exceeding the 1000x-1500x limit of light-based systems. Dissecting microscopes have low magnification for larger specimens, and phase contrast microscopes are specifically designed to enhance contrast in transparent live cells.