We have already discussed about image formation in a pinhole camera and on a mirror.
Is there any difference in both of these images?
Yes, there is a difference in image formation by a pinhole camera and a plane mirror. Let us see the differences in the tabular column given below.
|The images that can be captured on screen are called real images.||The images that cannot be captured on screen are called virtual images.|
|Real images are always inverted.||Virtual images are always upright.|
The image formed on the pinhole camera and cinema screen.
The image formed on the plane mirror and concave lens.
Properties of images formed on a plane mirror
- The plane mirror always forms virtual and upright images.
- The object size and image size are always equal.
- The image distance from the plane mirror is equal to the distance of the object from the mirror.
- Images are laterally inverted.
Is it possible to transfer information (data) from one place to another by using light rays?
Yes, we can use a device called optical fibre.
- Optical fibre works on the principle of 'total internal reflection'. By using optical fibre, we can transfer huge amount of data over a large distance.
- Optical fibre consists of a cable with thin, flexible fibres with a glass core through which light signals are sent.
- They can be twisted and bent easily.
- The data which is given to the optical fibres are in the form of pulses of light.
- The data which is given at the one end reaches the other with negligible losses.
- Optical fibres have become very important in high-speed communications, such as cable television and high-speed broadband services because we can transmit data very easily with negligible loss.
Working of optical fibres