Physics

Chapter - 9: Refraction of Light

👉 All Chapter Contents 👈 

• 9.1 Refraction of light
• 9.2 Total International Reflection
• 9.3 Uses of Refraction
• 9.4 Types of Lenses
• 9.5 Function of the Eye

Which characteristics of light is used to make optical fiber?

Total internal reflection of light is used to make optical fiber.

How much is the refractive index of glysarine?

Refractive index of glysarine is 1.47.

How much is the refractive index of diamond?

Refractive index of diamond is 2.417.

What is optical fibre?

Optical fibre is made of very long thin flexible but solid glass or plastic fiber. Optical fibre is used to carry light.

How much is the refractive index of air?

Refractive index of air is 0.88.

What is principal axis?

The straight line passing through the two centres of curvature of the two spherical surfaces is called the principal axis.

What is convex lens?

The lens whose mid portion is thick but the edges are thin is called convex lens.

What is plane convex lens?

The lens whose one side is plane and other side is convex is called plane convex lens.

What is sclerotic?

Sclerotic is composed of white, strong and dense fibrous tissues. It protects the eyes and save them from any external hazards.

What is choroid?

There is a deep black layer on the inner side of sclera. This is called choroid. Due to this black layer light is not reflected internally within the eye.

What is iris?

Just behind the cornea, there is an opaque diaphragm. It is called iris. The color of iris may vary from person to person. Usually the color of iris is black, light azure or deep brown. Iris regulates the amount of light falling on the eye lens.

What is vitreous humour?

The jelly like substance that fills the gap between retina and eye lens is called vitreous humour.

How much time is the persistence of vision?

Persistence of vision is about 0.1 second.

What is the distance of distinct vision of eye?

The distance of distinct vision of eye is 25 cm.

What is aqueous humour?

The saline watery fluid that fills up the space between the eye lens and cornea is called aqueous humour.

For what incident of light can we see mirage in desert?

Mirage occurs due to total internal reflection of light. The sandy surface of desert is rapidly heated by tremendous heat coming from the sun. So, the layers of air in contact with the sandy surface become hot. As a result the lower layers become hot and lighter but the upper layers are comparatively colder and denser. The ray of light coming from the tree enters continuously into rarer medium from denser medium. As a result the refracted ray continues to go away from the normal. In a certain moment the ray of light incidents on a layer at an angle which is greater than the critical angle and total internal reflection occurs. At that time the upside down image is seen and we call it mirage.

What are the used of optical fibre?

There are many uses of optical fiber. They are given below-

A set of optical fiber is called optical tube. An optical tube is passed through the mouth to stomach in order to examine the inner wall of the stomach of any patient. A set of optical fiber of this optical tube is sent to  lighten the stomach and the other set helps to see the lightened portion of stomach from the outside. The process is known as endoscopy. In this way by sending optical tube the block inside the artery, vein and function of valves of heart can be observed. Optical fiber is used for sending or receiving electrical signals from one place to another. Before sending, the electrical signal has to be converted into optical signal. Near about 2000 telephone signals can be transmitted at a time through a single optical fiber. Almost no change takes place to the intensity of the signals for this kind of transmission. The use of optical fiber at present has brought about a significant change in communication system.

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