"What is the name of the yellow objects?"
Translation:Hvad er navnet på de gule genstande?
No, it is always "navnet på".
No, "navn(et)" is a noun.
The English in this sentence is wrong, you'll need to fix this, and adjust the Danish sentence accordingly. Please act on this.
Your report would be more useful if you indicate what you thought was wrong and ideally even proposed a list of recommended alternatives which you consider correct.
I can't see a problem with the sentence myself.
Perhaps "what is the name" should be changed to "what are the name" since "yellow objects" are plural
No. Just as we don't say "The father of my children are called Steve".
The subject is "the name of the yellow objects", not "the yellow objects" -- and that subject is singular because "the name" is singular.