What is the note at the 0 fret of the 2nd (B) string?

The note at the 0 fret of the 2nd string, which is also known as the B string, is indeed B. In standard tuning, the strings of the guitar are tuned to specific notes, with the lowest sounding string being the 6th string (E) and progressing to the 1st string (E). The 2nd string is specifically tuned to B. Therefore, when you pluck the string at the open position, it produces the note B.

Understanding the standard tuning helps solidify the knowledge of fretboard notes. Each string represents a specific note, and knowing that the 2nd string is B clarifies why that is the sound produced without pressing down on the fretboard.