The Total solution for NCERT class 6-12
Asmall candle, 2.5 cm in size is placed at 27 cm in front of a concave mirror ofradius of curvature 36 cm. At what distance from the mirror should a screen beplaced in order to obtain a sharp image? Describe the nature and size of theimage. If the candle is moved closer to the mirror, how would the screen haveto be moved?
Size of the candle, h= 2.5 cm
Image size = h’
Object distance, u= −27 cm
Radius of curvature of the concavemirror, R= −36 cm
Image distance = v
The image distance can beobtained using the mirror formula:
Therefore, the screenshould be placed 54 cm away from the mirror to obtain a sharp image.
Themagnification of the image is given as:
The height of the candle’simage is 5 cm. The negative sign indicates that the image is inverted and real.
Ifthe candle is moved closer to the mirror, then the screen will have to be movedaway from the mirror in order to obtain the image.