First of all, in standard lots (100,000 units of BASE currency), 1 pip might be worth $10 (not $1). Specifically, 1 pip will be worth $10 per standard lot, if and only if, BOTH the account currency AND the quote-currency in the pair being traded are USD. In similar fashion, 1 pip will be worth £10 per standard lot, if and only if, BOTH the account currency AND the quote-currency are GBP. This occurs only in the EUR/GBP pair. In every other GBP pair, the GBP is the BASE currency, not the quote-currency.