The defect where rays of different colours fail to converge at a single point after passing through a converging lens is termed

Step-by-step solution

The refractive index of the material of a lens varies with the wavelength (colour) of light. Since the focal length of a lens depends on the refractive index, rays of different colours have different focal lengths and fail to converge at a single point after passing through the lens. This defect is known as chromatic aberration.