An overhead projector (OHP), like a film orslide projector; uses light to project an enlarged image on a screen. In the OHP, the source of theimage is a page-sized sheet of transparent plastic film (also known as foils) with the imageto be projected either printed or hand- written/drawn. These are placed on the glasssurface of the projector, which has a light source below it and a projecting mirror and lens assembly above it as shown in the figure

(i)Based on the diagram shown, what kind
of lens is used to make the overhead
projector?
(a) concave lenses (b) convex lenses (c)
bifocal lenses (d) flat lenses

(ii) The image obtained will be erect and
real. How?

(a) The image when passed through
the lens was erect and was directly
obtainedon the screen.
(b) The image when passed
through the lens was inverted
and then it gets reflectedon the
mirror to be obtained on the
screen.
(c) The screen used automatically makes
the image erect and real.
(d) Both (b) and (c)

(iii)Why is concave mirror used and not
convex mirror?
(a) because concave mirror can give real
image.

(b) because convex mirror can give real
image.
(c) concave mirror cannot give real image.
(d) because convex mirror cannot give
virtual image.