High capital mobility = impact on what happens on interest rates
For example, expansionary monetary = increasing money supply (by lowering rates), if rates fall, currency will depreciate as people move money out ….. Expansionary fiscal = increasing borrowing = higher rates = currency appreciates = impact is not clear (as rates moved in different ways)
Low capital mobility = impact on trade flows, think of what happens to GDP… for example, expansionary fiscal or monetary policy = bank is trying to raise GDP = higher imports (as people have more money) and lower exports = currency depreciates (since there’s less foreign demand for domestic products)
I hope that helps