An astronomical telescope has a magnifying power 10, the focal length of the eye-piece is 20 cm. The focal length of the objective is |
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a) |
b) |
c) |
200 cm |
d) |
2 cm |

An astronomical telescope has a magnifying power 10, the focal length of the eye-piece is 20 cm. The focal length of the objective is |
|||||||

a) |
b) |
c) |
200 cm |
d) |
2 cm |

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