P-1 Lenses Science - P-1 Lenses

In simple microscope _____________ lens is used.

The power of convex lens of focal length 20 cm is ______________.

The power of a convex lens of focal length 25 cm is ______________.

For the normal human eye, the near point is at ___________ cm .

The ____________ controls the amount of light entering the eye.

Simple microscope is used for watch repairs.

The focal length of a convex lens is 20 cm . What is its power?

Observe the following figure and complete the table:

	Points	Answers
i.	Position of the object	---------------------
ii.	Position of the image	---------------------
iii.	Size of the image	---------------------
iv.	Nature of the image	---------------------

Focal length of a convex lens is 25 cm . What is its power?

Write down any two rules used for drawing ray diagrams for the formation of image by convex lens.

Surabhi from std, X uses spectacles. The power of the lenses in her spectacles is 0.5 D . Answer the following questions from the given information:
i.Identify the type of lenses used in her spectacles.
ii. Identify the defect of vision Surabhi is suffering from.
iii. Find the focal length of the lenses used in her spectacles.

i. What is the minimum distance of distinct vision for normal human eye?
ii. Identify the defect of vision shown in the figure :

iii. Define power of a lens.

Doctor has prescribed a lens having power +1.5 D for correction of eye defect. What will be the focal length of the lens? What is the type of the lens and what must be the defect of vision?

Observe the figure and answer the following questions:

i. Name the defect of vision represented in above figure.
ii. State the reasons for this defect.
iii. How is it corrected?
iv. Draw the diagram to show the correction of this defect.

Draw a scientifically correct labelled diagram of a human eye and answer the questions based on it:
i. Name the type of lens in the human eye.
ii. Name the screen at which the maximum amount of incident light is refracted?
iii. State the nature of the image formed of the object on the screen inside the eye.

(a) Draw a neat labelled diagram of human eye.
(b) What is the minimum distance of distinct vision for a normal human eye ?
(c) Name the capacity of the eye lens to change its focal length as per need.
(d) Name the defect of eye vision in which the focussing power of eye lens decreases with age.

A concave lens is a converging lens.

When the incident ray is parallel to the principal axis, the refracted ray does not pass through the principal focus.

Simple microscope is used for watch repairs.

Write the defect of eye from the given figure:

True or False :
A concave lens is a converging lens.

Find An Odd One Out :
Camera, Telescope, Peephole in door, Microscope

Name the Following :
Write the defect of eye from the given figure:

True or False :
When the incident ray is parallel to the principal axis, the refracted ray does not pass through the principal focus.

True or False :
Simple microscope is used for watch repairs.

Camera, Telescope, Peephole in door, Microscope

Torch: Concave lens :: Camera: ______________.