Page 143 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

close to the lens. A Concave lens is also called a diverging lens as it diverges the light

rays passing through it.

Focal Focal
Point Axis Axis Point

Focal length Focal length
Concave lens Convex lens

Diverging and converging lenses

2. Draw the formation of colours when a light ray passes through a glass prism.
Ans:

White light splits when it passes through a prism

3. What type of mirror is used as a side mirror in a car? Why?

Ans: A convex mirror is used as a side mirror in a car. This is because convex mirror provide
a wider field of view, allowing drivers to see more area behind & to the sides of the

car. This also helps in reducing blind spots & improving safety while driving.
Additionally, objects in convex mirrors appear smaller, which mean they seem farther

away, allowing the driver to perceive a larger area.

4. Two different types of lenses are placed on a sheet of printed paper. How will you
identify them without touching?

Ans: We can observe the following:
(a) Convex lens - When we look through a convex lens at the printed paper, the

text will appear larger & magnified. This lens converges light rays which causes

the magnification effect. Additionally, the image may appear inverted if the lens
is held at a certain distance from the paper.

(b) Concave lens - When we look through a concave lens at the printed paper, the

text will appear smaller & reduced in size. This lens diverges light rays, leading

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