I don't know *why* i find it so interesting but i find it fascinating that Indian English uses the word "doubt" to mean "question"--as in, "ask a doubt" instead of "ask a question"
I don't know why that particular grammar quirk has happened but it's a weirdly interesting one. maybe just interesting because we encounter it a lot; there's a lot of Indian people doing things in electrical engineering so you see online reference material written in Indian English a lot
-F