Once a sound recording is made, how is the sound reproduced? by converting passive sound waves into active sound waves by converting sound waves into electronic signals by converting the electronic signals back into sound waves by speeding up the stored sound waves

by converting the electronic signals back into sound waves

Explanation:

When sound is recorded then we convert the sound energy into electrical energy and store it on the magnetic tapes

Now when we have to convert this energy again into sound then we use the reverse phenomenon.

So in this reverse phenomenon we have to convert the electrical energy stored on the magnetic tapes into the sound energy so overall we can say that correct answer will be

by converting the electronic signals back into sound waves

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

measuring things 1 litre of water