100+ GK Current Affairs Questions and Answers Pdf - 1

Question: 1

What is lens?

A lens is a portion of a transparent refraction medium bounded by two spherical surfaces or by one spherical surface and on the other side a plane surface.

The different types of lenses are

Double convex or Biconvex lens

Plano convex lens

Concave lens

Double convex concave lens.

Question: 2

What is an optical fibre?

An optical fibre is a device based on total internal reflection by which a light signal can be transmitted from one place to other with negligible loss of energy.

Question: 3

What are the uses of lenses?

It is used in making spectacles, cameras and microscope and many other optical instruments.

Question: 4

Define principal axis and Optic centre of lens?

Principal axis: The line joining the centres of curvatures of two spherical surfaces is known as the principal axis.

Optic centre of lens: The optic centre of a lens is defined as a fixed point lying in between the two spherical surfaces. A ray of light passing through it suffers no deviation.

Question: 5

Mention the applications of optical fibres?

Optical fibres are used by the doctor in endoscopy.

It is used to carry telephone message and computer data accurately.

It is used to destroy tumors in solid organs like liver.

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