What are examples of optical waves?

The electromagnetic wave of wavelength $1500 \mathrm{nm}$ lies in which region of the spectrum?

Consider the following
(i) Submarine communications
(ii) A.M. radio
(iii) Shortwave ratio
(iv) Radar

Arrange the above in increasing frequency of the waves associated with them

The wavelength of visible light is between _____ $\mathrm{nm}$ and $800 \mathrm{nm}$.

The wavelength of Ultraviolet rays is between _____ $\mathrm{pm}$ and $400 \mathrm{nm}$.