Describe the working principle of a pinhole camera and explain why the image formed is always inverted.
Options
It uses a lens to focus light, forming an upright image.
Light travels in straight lines and passes through a tiny hole, forming an inverted image on the screen.
It reflects light multiple times internally to produce a magnified, upright image.
It scatters light to create a diffuse, blurred image that is always upright.
Explanation
A pinhole camera works on the principle that light travels in straight lines (rectilinear propagation). Light rays from different points of an object pass through a tiny pinhole aperture and fall onto a screen inside the camera. Since the rays from the top of the object travel downwards to the bottom of the screen, and rays from the bottom of the object travel upwards to the top of the screen, the image formed is always inverted (upside down) and laterally inverted (left-right reversed). Options A, C, and D describe incorrect mechanisms or image properties for a pinhole camera.