Explanation : A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum.
Cathode ray oscilloscope is an electronic display device containing cathode-ray tube (CRT) that generates an electron beam used to produce visible patterns or graphs on a phosphorescent screen.
A sonometer is an apparatus made of hollow box having two holes. A string is attached to it by which the transverse vibrations of strings are studied. ....Read more