(INSPIRON 5559) CRACKLING SOUND WHEN UNPLUGGING ADAPTER, WHY?

I recently bought a Dell inspiron 5559 (June 1, 2017). I then noticed that whenever I play audio like music or videos and plug the adapter out, I would hear a crackling sound, sounds as if its coming from the speakers. When I pause the sound and unplug then play audio the sound is made so I'm guessing the problem seems to exist whether I play audio or not. No matter where I plug the adapter out, it makes that sound. I'm worried that it might destroy the laptop, or that this is a defect that might start a fire if its a lack in how the adapter was made. It is a 45 w adapter according to what is labelled on it. sometimes i get a message saying "adapter is not recognized. system performance will be impacted etc" and I guess it happens if I don't plug the cord in properly? or is it not suppose to say that at all? Nonetheless, my main worry is the sound the laptop makes when I unplug the adapter. It goes on for maybe 3 or 4 seconds and sounds like a radio transceiver. Please comment if you know what this means, Thank you.