A
Light sources are called_________ because they emit light.
Luminous bodies
What is a ray?
A straight line with the overhead which shows the path and direction of light.
Define beam?
A bundle of light rays.
What is a shadow? (Define)
A dark patch formed behind an opaque object , when light rays are blocked by that object.
What is an eclipse?
The process of casting a shadow by a celestial bodies.
Pinhole camera shows the ________ image.
a. fake
b. duplicate
c. mirror
d. real
d. real
Define penumbra.
The region of shadow of partial darkness , where some of the light is blocked.
Define Light.
Light is a form of energy which helps us to see the world around us.
A solar eclipse occurs on a ________ day.
new moon
Name any 3 applications of rectilinear propagation of light?
*Formation of shadow
*Solar and lunar eclipse
*Pinhole camera
*Phase of the moon
* Camera and photography
What is a divergent beam?
Ina divergent beam of light , light rays from a source travel in different directions , that is, they diverge.
Unscramble the word:-
ECILNEIRATR
RECTILINEAR
What is a convergent beam?
In a convergent beam of light , light rays from a source converge at a point.
Unscramble the word:-
TESNARTPRAN
TRANSPAERNT
Choose the odd one out
transparent ,translucent , shadow , opaque
shadow-As it is does not allow light to pass through it .
Unscramble the word:-
EOPILNH
PINHOLE
Define Opaque , Translucent and Transparent objects?
Opaque-Materials that do not allow any light to pass through them.
Translucent-Materials that allow some amount of light to pass through them.
Transparent-Materials that allow all the light to pass through them.
Give 4 examples of luminous and non-luminous objects.
Luminous objects- Sun, candle, torch and firefly.
Non-luminous objects- Trees, house, human beings and stone etc.
Moon is a _________ of sunlight.
a. representative
b. reflection
c. reflector
d. shadow
C. Reflector
Define umbra.
The region of total darkness of shadow , where all the light is blocked by the object.
Define Pinhole camera?
Pinhole camera is a simple camera with a tiny hole but without a lens. It is an interesting and simple photographic device, which works on that light travels in a straight line.
If we are in the penumbra region we can experience a _______________________.
partial solar eclipse
Any source of light which is bigger than the point sorce is called the _________________.
Extended source of light
The presence of ____________causes the blurred edges around the umbra region.
penumbra
Define rectilinear propagation of light?
It works on the principle that light light travels in a straight line and passes through the pinhole.