What are Real and Virtual Images? Video Lecture | Science Class 7

real and virtual images at the end of
the session you will be able to explain
the difference between a real and
virtual image explain how real and
virtual images are formed what does the
difference between a real image and a
virtual image the image you can see on a
screen at a cinema hall is a projection
of the film on the screen and it is a
real image a real image is a
representation of an actual object that
is a source formed by rays of light
passing through the image if a screen is
placed in the plane of a real image and
becomes visible that is real images are
formed where rays of light actually
converge the image formed by a
reflection on a plane mirror is
described as a virtual image virtual
images are formed when rays of light are
perceived to converge if you stand in
front of a mirror and image seems to
form behind the mirror
if you move back the image also moves
back in reality there is no image behind
the mirror therefore an image which
cannot be formed on a screen as a
virtual image real images let us now
understand how real and virtual images
are formed when light from an object
enters our eyes it's really majors
formed on the retina which is the screen
of the eye this image is smaller than
the object and is inverted the brain is
able to analyze that light travels in
straight lines it is able to calculate
the direction distance and size of the
object therefore when you see the image
of an object it is correct in size in
the correct direction at the correct
distance and upright
virtual images however at certain times
the brain is unable to analyze correctly
for example if a ray of light coming
from an object at point in bents at
point O and then reaches our eyes the
brain is unable to perceive that the
light reaching our eyes is vent at point
O now since the brain is only able to
analyze that light travels in straight
lines it assumes that the light reaching
our eyes is from the point V therefore
we can see that the object is positioned
at point B although in reality the
object is positioned at Point a so we
can see that the B is the virtual image
of a because it only seems that the
light is coming from the virtual image
pinhole camera now let us understand the
concept of real images for the help of a
pinhole camera to make your pinhole
camera you will need a cardboard box
tracing paper black paper a craft knife
glue or tape take a small box with all
the sides closed except one side cut a
piece of tracing paper cover and paste
it to the open side of the box using
glue or tape this forms the screen of
your camera cut a small square at the
center of the closed end on the opposite
side of the box and then paste a piece
of black paper to cover this cut area
make a small hole in the paper now light
is able to enter the box through the
small bowl focus your camera towards an
object image of knob check falls on the
tracing paper screen a light ray from
point 8 passes through the pinhole and
falls on the screen at C a ray from the
beam falls a deal
similarly rays of light from each point
on an object passes through the pinhole
and falls on the screen collectively
these points of light create the image
although this image is inverted it is a
real image let us summarize a real image
is a representation of an actual object
that is a source form by rays of light
passing through the image the image
formed by a reflection on a plane mirror
is described as a virtual image a real
image is smaller than the actual object
and the images inverted