I'm often the dumbest person on a Zoom call. Seriously. I talk to a lot of people who are experts in their field (data science, AI, global supply chains) and I rely on their expertise to educate me so that I can write a story and inform others.
So, I ask a lot of questions. I try to do my homework before I interview someone, but I still have to ask a lot of questions because I can't assume anything. I have to make sure that I understand these experts and can accurately convey the information they provide me.
The reason it doesn't bother me that I'm the dumbest person on the call is because I've never had anyone be rude about it. If you show a genuine interest in a person and the subject, they're always willing to answer your questions.
I think it's important that everyone be the dumbest person on a call or in a room throughout their career. You need to be challenged and learning something new all the time, even if it doesn't have a direct link to your job. By stretching yourself and asking questions, you expand your network with people outside your field, you jumpstart your creative juices and you improve your communication skills.
If you can, do some homework before such conversations to show the other person that you're trying to get up to speed. But, if you don't have time to do research, then freely admit that you're learning and are going to be asking a lot of questions and plan to continue research after the call or meeting.
When you try to fake it and act like you know what the other person is talking about, you dig yourself a hole. Because sooner or later it's going to become evident that you're clueless and that will only annoy the other person.
So, go ahead and admit you don't know everything. But do admit that you want to learn and grow -- that will be welcomed by everyone.