Using Nikon AF-G lenses on a Nikon FM-10 35mm film slr camera?

My friend used his 18-55mm 3.5-5.6 on his school photo class FM-10. There's no aperture ring on that lens so I wonder how the camera choose what aperture to use? My friend doesn't really know what happens when you do that but he guesses it uses 3.5-5.6 dependimg the the focal length, but what if you want to use F6.3 or smaller? I want to know this because I might take the class next
year and use my 50mm 1.8G on the FM-10 if the camera actually chooses a smaller aperture on it's
own. I wouldn't want it to be stuck on F1.8. The class only uses b&w 100 speed film and no flash.

Added (1). He was trying out the G lens on it because he says he doesn't like the 35-70mm lens that he's suppose to use on it. I'll probably use the lens that comes with it because G lenses do not work on film cameras.

Actually it works the other way; the G lenses will stay at the smallest available aperture, which is probably f/22 or thereabouts (I don't have that specific lens). You can't really use a lens that way all the time, especially with ISO 100 film. Fortunately, a used 50mm 1.8 Series E manual-focus lens is only like $30.

edit:
I should also mention that your FM-10 won't meter correctly with G lenses. If you use the TTL meter, you'll underexpose everything.

This sounds like a giant mess that would best be discussed with your teacher and your friend all at the same time.

1--AF-G lenses are not compatible with the FM-10. They'll mount but using them effectively is a pointless task for exactly the reason you've stated.

2--Your friend isn't learning much from the class if he/she does not know what aperture he/she is using to take the photo. You can't learning anything about depth of field, aperture or exposure if you don't even know what aperture you're using in each photo. This is the point of using a fully adjustable, manual camera as oppose to a point and shoot.

3--Why not simply purchase the correct lenses for these FM-10's instead of forcing digital lenses onto them? The correct lenses (AI, AIS, E Series) are cheaper and better built than AF lenses anyway. Plus, these lenses can be used on DSLR's. Your friend really shouldn't even be using a zoom lens for class anyway. A 50mm is the best lens to learn 35mm film with. Using a zoom, even one that works right on the camera, results in confusion over predicting and understanding depth of field.

Go to KEH.com and buy yourself a 50mm f2, 1.8 or 1.4 AI, AIS or E Series Nikon lens so you can stop worrying about the camera and start learning the basics of photography! Help your friend out too!

METAL AND MANUAL! FILM FOREVER!