Not on the iPad (of any generation), no.
To the best of my knowledge, there is no transformer inside the iPad from what I can remember seen from the device tear-downs, so from a "let's think this through logically" point of view, I'm just not sure what could be inside the iPad which would cause the buzzing. If it is your iPad which is buzzing and/or leaking current to the casing, then we're in strange new territory here.
On the other hand, issues with buzzing adapters when plugged in are well-known and I have encountered them frequently with laptops. I have personally not heard of an Apple charger which buzzes - but it is essentially a transformer that steps-up or steps-down the current from the wall socket to supply your device, so it if makes a similar noise, it's a safe assumption that it's a defective transformer.
Out of millions of parts and devices that Apple ship, some of them are bound to be defective out-of-the-box - so a bit of bad luck here, unfortunately.
