[alshaymah]

What happen to the direction of the single ray that passes the center of the concave lense.

And

What happen to the direction of the single ray that passes the center of the convex lense.

...

I think through the convex it will go in straight line and will meet with other rays on the
Focal point.

For the concave I think it also will go in straight line.

But the other rays will diverge and its remain rays will meet behind the lense on the

Focal point. The ond that passes on the center am not sure about it.

[Capuchin]

You know that if a ray of light is perpendicular to a surface, it doesn't experience refraction (because it is travelling along the normal), so yes you are correct.

However the question is ambiguous, a ray can still travel through the center of the lens but be incident from a different angle, in this case the result would be different as the ray is not travelling along the normal.

However, I think your teacher wanted you to think about the case where it is travelling along the normal, and "it doesnt bend" is the correct answer in that case. Well done! :)

[alshaymah]

you know that if a ray of light is perpendicular to a surface, it doesnt experience refraction (because it is travelling along the normal), so yes you are correct.

However the question is ambiguous, a ray can still travel through the center of the lens but be incident from a different angle, in this case the result would be different as the ray is not travelling along the normal.

However, I think your teacher wanted you to think about the case where it is travelling along the normal, and "it doesnt bend" is the correct answer in that case. Well done! :)

Thank you :D
I hope the test will be as this simple :o