These phrases are almost synonymous and there isn't much difference between them when they are used in a positive sense:
You are expected to (=should) finish your work before you leave.
You are supposed to (=should) finish your work before you leave.
They convey completely different meanings when they are used in a negative sense:
You are not supposed to (=should not/ prohibited to) use the office phone for your personal needs.
You are not expected to (do not have to) use your personal phone for official purposes.
for more information
http://franchisee.veta.in/
You are expected to (=should) finish your work before you leave.
You are supposed to (=should) finish your work before you leave.
They convey completely different meanings when they are used in a negative sense:
You are not supposed to (=should not/ prohibited to) use the office phone for your personal needs.
You are not expected to (do not have to) use your personal phone for official purposes.
for more information
http://franchisee.veta.in/