Actually, I believe it is "Bob's passion" however, the way you are wording it, I believe it would be "a passion of Bob."
It would be "Bob's paper was incomplete." Bob's
it would be bob's unless there were multiple bobs or the persons name was bobs.
bob is in charge of the the bobtown bobs and the bobs meet bobby bob
It is Bob's house. The apostrophe "s" after Bob indicates that the house belongs to Bob.
bob
wat is a bob LOL
then he is bobs uncle
password of Stompin bob is CLubPenguinStompinbob
he went to your town
bobs big boy
Brian Stanton
Your mums a bob set