Question

Explain the formation of the image of a luminous object in a pinhole camera with the aid of a neat diagram.

Answer 1

When a luminous object AB, such as a lighted candle, is placed in front of the pinhole, an inverted picture A’ B’ of the candle is
obtained on the tracing paper. This picture A’ B’ is called the image. The image obtained is upside down (i. e. inverted). The reason is that the light travels in a straight-line path. Hence light from the upper point A of the candle passes through the pinhole and strikes
the tracing paper at A’. Similarly, light from the lower point B of the candle passes through the pinhole and strikes the tracing paper
(or screen) at B’. Light from all the other points between A and B, on passing through the pinhole strikes the tracing paper in between
A’ and B’. As a result, an inverted image of the candle is seen on the tracing paper Fig shows the simple ray diagram for die formation of the image.