What happens to light rays that pass through a lens?
They are absorbed
They are reflected
They are refracted
What type of lens is thicker in the middle than at the edges?
Convex
Diverging
Concave
Which type of lens causes light rays to diverge?
Converging
Which type of lens is used in a camera?
What type of images do convex lenses form?
Real images only
Both real images and virtual images
Virtual images only
What types of images do concave lenses form?
What name is given to the distance between the lens and the principal focus?
Focal length
Principal length
Principal axis
Where should the object be placed to use a convex lens as a magnifying glass?
Inside the focal length
Between F and 2F
Beyond 2F
What is the unit for the power of a lens?
Metres
Watts
Dioptres
What is the focal length of a 6.67 D lens?
0.15 cm
15 cm
67 cm