Oh ya, there are! It’s not a sign of intelligence or attention to machine-gun irrelevant questions.

A less bullshit version could be:

Don’t be afraid of asking dumb questions.

Or better still:

Listen carefully and try to ask relevant questions that help you understand what you don’t understand. Sure, there is a chance that your questions turn out to have been dumb, but that’s OK, it’s all a part of the learning process.