a.  The wavelength of visible light is between 400 nm and 800 nm.
b.  GMRT is used for radio waves.
c.  A certain X-ray telescope is named after scientist Subramanian chandrashekhar.
d.  The first scientist to use a telescope for space observation was Galileo Galilei.
e.  The biggest optical telescope in India is situated at Aryabhatt Research Institute of Experimental Sciences, Nanital.