Or even:

Do you know that photocopiers store image on a hard drive? 1) Yes 2) No

vs

When you photocopy an image, the photocopier... 1) saves the image to a hard disk permanently. 2) temporarily stores the image until the copy is finished. 3) other

The first question leads people to lie in order to not be seen as ignorant.

>Do you know that photocopiers store image on a hard drive?

Is still pretty leading. People would say yes because they don't want to appear naive.

"Do photocopiers keep any records of copies made?"

Ah, but in that case you'd get fifty-fifty since people who had no idea would just guess.

I was considering it as an open question not a yes/no. If they say yes you ask them how. That way they are demonstrating their knowledge rather than claiming it.

Like if you wanted to find out if people know that bacon flavour crisps are vegetarian you'd ask something like "do any crisps contain meat or animal products?" and be prepared with follow on questions. So if the response is "no" you go back with "not even BBQ beef or bacon flavour?". If they answer "yes" you ask "out of these, which are suitable for vegetarians: ..." or somesuch.