Laptop power adapter sparking noise

I just got my Refurb Dell XPS studio 16 3 days ago, and there was a weird sparking noise(nothing visible) coming from the brick. So, I disconnected the adapter and plugged it back in. That reduced the noise, to where I can only hear it if I stick my ear to the brick.

I called Dell Tech support and they said they will send a replacement. So, 2 questions

1) Is it normal to hear that sound if you put your ear next to the adapter(It's like some sparks are going on inside)

2)Also-I recieved a 3 pin adapter with the comouter, from which I broke off one pin since my apartment has only 2 pin wall sockets. When I ship the orignal adapter back to Dell will they charge me for sending back the adapter with a broken pin?

Thanks