Question

electromagnetic wave of wavelength 1500 nm lies in which region of the spectrum

Answer 1

Wavelength range of infrared region is 10³nm - 10⁶nm.
It means given wavelength 1500 nm = 1.5 × 10³nm lies infrared region
Because wavelength 1.5 × 10³nm lies between 10³nm to 10⁶nm.
Typical sources of infrared region is cool cloud of dust and gas : planet , satellite.
Here I attached pic of electromagnetic radiations. I hope it will help you .