The focal length of the field lens (which is an achromatic combination of two lenses) of telescope is . The dispersive powers of the two lenses in the combination are 0.024 and 0.036. The focal lengths of two lenses are |
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a) |
30 and |
b) |
30 and |
c) |
45 and |
d) |
15 and |

The focal length of the field lens (which is an achromatic combination of two lenses) of telescope is . The dispersive powers of the two lenses in the combination are 0.024 and 0.036. The focal lengths of two lenses are |
|||||||

a) |
30 and |
b) |
30 and |
c) |
45 and |
d) |
15 and |

1 Answer

127 votes

For achromatic combination and Solving above equations we get |

127 votes

127