Two lenses of power – 15D and +5 D are in contact with each other. The focal length of the combination is |
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a) |
-20 cm |
b) |
-10 cm |
c) |
+20 cm |
d) |
+10 cm |

Two lenses of power – 15D and +5 D are in contact with each other. The focal length of the combination is |
|||||||

a) |
-20 cm |
b) |
-10 cm |
c) |
+20 cm |
d) |
+10 cm |

1 Answer

127 votes

Power of lens is reciprocal of its focal length. Power of combined lens is |

127 votes

127