How can we pronounce the number "0" in British English? I mean: telephone numbers, room numbers etc.
Which form is correct and where (why)?
Do we use "nought" or "zero" in science in British English?
In UK English noun nought does mean zero. This is different from naught, which means nothing. In US English they are spelling variants of the same word, and naught is the more standard usage for both meanings.
When reading a number out loud many English speakers will say o (pronounced owe) as in the letter O when meaning the digit zero.
So: "room 702" is often said "Room Seven O(we) Two" while "Seven Zero Two" is also used. I don't believe I've ever heard someone say "Seven Nought Two". Similarly O(we) is used when reading out phone numbers, though my preference is to use zero when stating my own phone number.
But I think I hear "dial zero for the operator" far more frequently than "dial O(we) for operator."