February 28, 2023
REFLECTION AND REFRACTION-2
OUTCOMES

By the end of the lesson, students should be able to:
•
Predict the types of images formed by reflection from a plane mirror and
by refraction through a thin convex lens.
•
Relate the focal length of a lens to the location and magnification of an
image.
CHARACTERISTICS OF IMAGE IN A PLANE
MIRROR
1. The image will be the
same size as the object
2. It will be the
same distance behind the
mirror as the object is in
front of the mirror.
3. This image is called
a virtual image.
Law of Reflection

Law of reflection
states that the angle
of incidence is equal
to the angle of
reflection.
Drawing an image in a plane mirror

Ray diagrams of reflected
light from a plane mirror
can be drawn according
to the guidelines below:
•
An incident ray is drawn
straight from a point on
the object to the mirror.
A reflected ray is drawn
straight away from the
mirror.
•
Additional incident rays are
drawn from the same point
on the object but at an angle
to the mirror. Reflected rays
are drawn away from the
mirror at the same angles as
the incident rays.
•
Each reflected ray is extended
behind the mirror and used to
draw the image.
Question-1
Draw the image of David in the mirror.
2. Concave mirrors
Image in a concave mirror

Ray diagrams of reflected
light from a curved mirror
can be drawn according to
the guidelines below:
•
An incident ray is drawn
straight from a point on the
object to the mirror. A
reflected ray is drawn
through the focal point.
•
A second incident ray is
drawn from the same
point on the object
through the focal point to
the mirror. A reflected ray
is drawn straight away
from the mirror.
•
The reflected rays are
used to draw the image.
Types of image in concave mirrors

Concave mirrors can
form a variety of images,
depending on the
position of the object in
relation to the focal point
and the center of
curvature of the mirror.
1. An object far away
(at infinity) from the
mirror forms a real
image at the focal
point.
2. An object closer to the
mirror, just beyond the
center of curvature, forms
an image between the
center of curvature and the
focal point. The image is
real, inverted, and reduced.
3. An object placed
between the center of
curvature and the focal
point forms an image
beyond the center of
curvature. This image is
real, inverted, and
magnified.
4. An object placed
between the focal point
and the mirror will
produce a virtual image
(behind the mirror). The
image will be magnified
and upright.
3. Convex mirrors
Image in a convex mirrors

Convex mirrors
produce only virtual
images (behind the
mirror) that are
upright and smaller
than the object.
REFRACTION

Refraction is the
bending of light
when it passes from
one medium to
another.

Light changes direction
when it passes from
one medium to another
because it travel with
a different speed.
ANSWER THE FOLLOWING QUESTIONS ][10]
1. Draw the image of arrows in the plain mirror. [2]
2. Match words and their
place in the diagram. [6]
3. What is refraction. [1]
4. Find the place of images
in the mirrors.