Optics Conceptual Analysis

One or two sentences is fine. But please clearly explain eachquestion.

For each statement, decide whether it is always true, always falseor true in certain
circumstances. State which case applies to the statement,describing why you
chose the answer you did and cite an experiment or principle ofPhysics which
supports your claim.

[1] Mirrors can only produce virtual images.
[2] A lens which is thicker in the center than the rim will have apositive focal length when
surrounded by media with lower index of refraction.
[3] A point source of light is placed at the focal point of aconvex lens. The light emerging from
the other side of the lens is a parallel beam of light.
[4] An object and screen are 1 meter apart. A convex lens with afocal length less than 25cm
will form an image on the screen when placed at either of 2positions.
[5] Real images are formed by convex lenses and mirrors.
[6] An image an observer can see is a real image.
[7] All concave lenses are divergent lenses.
[8] The thin lens equation only works for visible light, not UV orIR.
[9] The index of refraction for a material is the same for allwavelengths.
[10] For total internal reflection, the index of refraction outsidethe material must be greater than
that of the material in which the light is travelling.