To be honest this topic is a huge and cant really be covered on an internet forum.
But a few pointers. INTEREST RATES can be raised or lowered and can have an impact on currency prices.
EXCHANGE RATES fluctuate on a second by second basis depending on supply and demand. There is no way of saying for certain whether demand will rise or fall, it is based purely on the psychology of the market.
Exchange rates are therefore not "raised" which would imply some governing body sets them. (although this does happen in certain economies, but generally not in the west).
In your example you talk about the USD. If the price of USD goes up relative to another currency, for example the EUR, the USD will be able to buy more euros. A German product that may have cost you the equivilent of $1000 yesterday, may cost you $950 today.
So assume you are a German selling to an American. You are going to get more demand for you product as the American customer can start to afford more of your products (because his currency is getting stronger).
So to put this in terms of your question German exports can be expected to increase as the USD rises.