Two thin lenses of focal lengths 
and 
are placed in contact with each other. The focal length of the combination is
a)
b)
c)
d)
Two thin lenses of focal lengths and are placed in contact with each other. The focal length of the combination is
a)
b)
c)
d)
Question ID - 152415 | SaraNextGen Top Answer
Two thin lenses of focal lengths and are placed in contact with each other. The focal length of the combination is
a)
b)
c)
d)
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Two thin lenses of focal lengths |
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a) |
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b) |
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c) |
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d) |
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1 Answer
127 votes
Answer Key / Explanation : (c) -
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(c) When From lens formula
Adding Eqs. (i) and (ii), we get
If this lens is replaced by a single lens, then focal length of combination is
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and 
are focal lengths of lenses combined together, image formation takes place as follows
127 votes
Answer Link
127