Graph Theory

[meszaj]

my english is not very good. so please be patient... i am learning for an exam (algorithms and data structures) and i have a few questions on graphs. i am not blonde but nevertheless this graph theory is hard for me to understnd. it would be grateful if anyone could answer this and correct my answers.also a short describtion why would be great
would below algorithms work, if one from lower conditions is fulfilled:
1. instead of shortest paths we are looking for the longest paths respectively so, that we only replace conditions bigger-smaller (>,<)
2. Graph has cycles
3. The edges also have negative values
4. when the graph is only one path
5. when the graph is not connected (incoherent)
6. can edges in graph also have path length equal to 0
7. if the graph is one alone cycle (the whole graph is one cycle)

A) KRUSKALs ALGORITHM
1.no
2.
3.
4.
5.
6.
7.
B) PRIMs ALGORITHM
1.yes
2.no
3.no
4.
5.
6.
7.
C) DIJKSTRAs ALGORITHM
1.yes
2.no
3.no
4.
5.
6.yes
7.
D) Critical Path ALGORITHM ( longest possible path )
1.yes
2.no
3.yes
4.
5.
6.yes
7.

thnx in advance