where should we move  the concave mirror towards the screen or away from the screen if we obtain a blurred image of a distant object in the practical of the finding of the focal length of a concave mirror .Also answer this question if in the place of concave mirror there is convex lens.

Asked by krishnapriya20 | 25th Feb, 2015, 05:53: PM

Expert Answer:

For a mirror or a lens, a sharp image is obtained only when the screen is at the focus of that mirror or the lens.
 
The image will be blurred if the screen is moved towards either side of the focus.
 
Hence, the concave mirror or the concave lens should be moved either towards or away from the screen.
 
If by moving it towards the screen the image is getting clearer, then continue moving towards or move it away.

Answered by Romal Bhansali | 26th Feb, 2015, 02:38: PM