Question

say all answers I will make brain list sure friends please try to say correct answers please​

Answer 1

Answer:

Human eye and colourfull world

Explanation:

1) A normal eye is unable to clearly see the objects placed closer than 25 cm because the ciliary muscles of eyes are unable to contract beyond a certain limit. If the object is placed at a distance less than 25 cm from the eye, then the object appears blurred and produces strain in the eyes.

2) The ciliary muscle to which eye lens is attached and helps to change its focal length by changing radii of curvature of eye lens. When the eye is focussed on a distant object, the ciliary muscles are relaxed so that the focal length of eye lens has its maximum value which is equal its distance from the retina.

3) Myopia can be corrected by wearing glasses/contacts with concave lenses these help to focus the image on the retina.

4) η = sin[(A+D)2] / sinA2

Where η is the refractive index of the prism, A is the angle of prism and d is the deviation. Using this formula, the refractive index of the material of the prism can be measured. A spectrometer can also be used to find the refractive index of a prism.

• 5) Take a metal tray and fill it with water.
• Place a mirror in the water such that it makes an angle with water surface.
• Now focus white light on the mirror through the water as shown in figure.
• Keep a white card board sheet above the water surface.
• We can observe the colours VIBGYOR on the board.
• The splitting of white light into different colours (VIBGYOR) is called dispersion.
• So consider a white light is a collection of waves with different wavelength.
• Violet has shortest wavelength and red has longest wavelength.

Answer 2

HUMAN EYE AND COLOURFUL WORLD

Answer the following

1) Why is normal eye not able to see clearly the objects kept closer than 25cm?

ans) A normal eye is unable to clearly see the objects placed closer than 25 cm becausethe ciliary muscles of eyes are unable to contract beyond a certain limit

If the object is placed at a distance less than 25 cm from the eye, then the object appears blurred and produces strain in the eyes.

2) How do you appreciate the working of the Ciliary muscles in the eye?

ans) The ciliary muscles to which eye lens is attached helps the eye lens to change its focal length by changing the radii of curvature of the eye lens.2 When the eye is focussed on a distant object the ciliary muscles are relaxed. So that the focal length of eye lens has its maximum value

3) How do you correct the eye defect Myopia?

ans) Myopia can be cured using the concave lens. This is because using the concave lens can bring the image of the object kept at some distance within the far point and point of least distance of the distinct vision with the help of the lens. This image will act as the object for the eye lens.

4) How do you find experimentally the refractive index of material of a prism?

ans) ⇒η = sin[(A+D)2] / sinA2 where η is the refractive index of the prism, A is the angle of prism and d is the deviation. Using this formula, the refractive index of the material of the prism can be measured. A spectrometer can also be used to find the refractive index of a prism.

5) Suggest an experiment to produce a rainbow in your classroom and explain the procedure?

ans) Suggest an experiment to produce a rainbow in your classroom and explain the procedure

1) Take a metal tray and fill it with water.

2)Place a mirror in the water such that it makes an angle with water surface.

3)Now focus white light on the mirror through the water as shown in figure.

4)Keep a white card board sheet above the water surface

5)We can observe the colours VIBGYOR on the board

6) The splitting of white light into different colours (VIBGYOR) is called dispersion.

7) So consider a white light is a collection of waves with different wavelength.

8) Violet has shortest wavelength and red has longest wavelength.

Now make me brainlist plss