Concepts Of Physics MCQ Edition [Volume 1]PhysicsSpeed of Light
An illuminated object is positioned on the principal axis of a converging lens such that a real image is produced on the opposite side. If the object is displaced by a small amount,
Options
- Athe image shifts a little later than the object
- Bthe image shifts a little earlier than the object
- Cthe image does not shift
- Dthe image shifts simultaneously with the object
Correct answer
A. the image shifts a little later than the object
Step-by-step solution
The speed of light is finite. When the object is displaced, the light rays from the new position of the object take a finite amount of time to travel to the lens and then to the image plane. Due to this finite propagation time, the information about the object's displacement reaches the image location after a small time delay. Therefore, the image shifts a little later than the object.