A) 20 cm
B) 10 cm
C) 25 cm
D) 30 cm
Correct Answer: B
Solution :
Image formed by lens \[\frac{1}{v}-\frac{1}{u}=\frac{1}{f}\] \[\frac{1}{\text{v}}+\frac{1}{30}=\frac{1}{20}\] \[\text{v}=+60cm\] If image position does not change even when mirror is removed it means image formed by lens is formed at centre of curvature of spherical mirror. Radius of curvature of mirror = 80 - 60 = 20 cm \[\Rightarrow \] focal length of mirror f = 10 cm for virtual image, object is to be kept between focus and pole. \[\Rightarrow \]maximum distance of object from spherical mirror for which virtual image is formed, is 10cm.You need to login to perform this action.
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