I have developed an ontology of emotions using Protege. I want to relate each class(emotion) of my ontology to its similar concepts in another ontology. For example, I have a class Anger. I want to retrieve concepts relating to anger, like agitation, mad, etc., in correct context from another ontology (ConceptNet or WordNet) through their URIs. How can I do so?
Is this even a correct idea to begin with? How else can I achieve my target? Can I call a class from another ontology from my ontology through URI within Protege?
If you only want to refer to the classes, you can simply use the same URI in both places.
However this does not force tools to actually take into account any axioms about those classes, i.e., your ontology will not know about superclasses or restrictions declared in the other ontology.
To actually use all axioms related to your other classes, you'll need to import the other ontology in its entirety. To only use part of the ontology, you can use one of various modularisation techniques available to create a subset of an ontology, containing the axioms you're interested in. However, the technique to use depends on your specific needs.
Can you provide more insight on what you are trying to achieve?
There's a lot of material online on modularisation - search for "ontology modularisation". Reading a few abstracts should help you focus on the best approach for your needs.