question_answer

The sun's diameter is \[1.4\times {{10}^{9}}m\] and its distance from the earth is \[{{10}^{11}}m.\] The diameter of its image, formed by a convex lens of focal length \[2\,m\]will be   [MP PET 2000]

A)            0.7 cm                                     

B)            1.4 cm

C)            2.8 cm                                     

D)            Zero (i.e. point image)

Correct Answer: C

Solution :

                   \[\theta =\frac{AB}{{{10}^{11}}}=\frac{{A}'{B}'}{2}\Rightarrow {A}'{B}'=\frac{2\times 1.4\times {{10}^{9}}}{{{10}^{11}}}=2.8\ cm\]