Civil Engineering - Surveying - Discussion
Discussion Forum : Surveying - Section 1 (Q.No. 22)
22.
Two concave lenses of 60 cm focal length are cemented on either side of a convex lens of 15 cm focal length. The focal length of the combination is
Discussion:
38 comments Page 3 of 4.
Akash said:
8 years ago
1/f = 1/f1+1/f2.
1/f = 1/60+1/60.
1/f = 1/30 answer.
1/f = 1/60+1/60.
1/f = 1/30 answer.
(1)
MANU said:
8 years ago
1/60 = 1/15 + 1/f2.
if we solve, it is coming 20.
if we solve, it is coming 20.
Neeraj Kumar singh said:
4 years ago
1/f = 1/15 - 1/60 - 1/60.
1/f = 1/30,
F = 30.
1/f = 1/30,
F = 30.
(5)
M.lokeswara Rao said:
1 decade ago
1/f = 1/f1+1/f2.
1/60 = 1/15+1/f2.
f2 = 30.
1/60 = 1/15+1/f2.
f2 = 30.
Saubhagya laxmi said:
1 decade ago
1/60-1/15 = -1/20 then how the answer z 30?
NAVEEN said:
6 years ago
1/f = 1/F1+1/F2.
1/60 = 1/15+1/F2.
F = 30.
1/60 = 1/15+1/F2.
F = 30.
(7)
Karan Dumbare said:
1 decade ago
1/f = 1/F1+1/F2.
1/60 = 1/15+1/F2.
F = 30.
1/60 = 1/15+1/F2.
F = 30.
Pawan kumar said:
1 decade ago
1/f = -1/60 -1/60 +1/15 = 1/30/
f = 30.
f = 30.
Aswin said:
1 decade ago
How is this calculated? Please explain.
Ratan pal said:
8 years ago
I think 1/f=1/15 -1/60 -1/60.
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