Answers:

Since BoP is always constructed on the basis of double-entry book-keeping, credit is always equal to debit. If the credit on the current account is lower than the debit, then funds will flow into the country and will be recorded as credit of the capital account. Thus, the excess of debit on the current account is balanced. Hence BoP is in equilibrium when the combined balance of current account and capital account is equal to zero i.e. the sum of debits and credits in the current and capital account is zero so that the official reserve account balance becomes zero.