Making a spectroscope is much more easier than I thought.
A spectroscope is basically an instrument to break the mixture of different wavelengths and let us see what it made up of.
I got to know what a spectrometer was, a couple of weeks ago(Luckily) and made one with the help of the guide Public lab has posted(I'll put the links at the end of the note).
Here's how it looks:-
Yeah, it looks ugly.I took a couple of pictures of the spectrum from different light source.
As you can see from the pictures the spectrum observed, the spectrum observed by the light emitted by the CFL is distorted or uncontinuous, whereas from the sun and the LED, it is very much continuous.
Thus we can conclude that the light from the CFL is not purely white. If it was, it should have contained all the 7 colours(VIBGYOR).It misses some particular wavelengths.It just contain narrow bands of violet, blue, green and orange color frequencies.
In case of LED the spectrum is somewhat like the spectrum from the sunlight. This is so because LEDs use blue chips which shines through a phosphor coating that turn the light white.