Power of combination of two lenses is 8 dioptre if one lens has focal length of 20 cm find focal length of other lens
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power of the combination is 8D
P=1/f f=1/P
f= 1/8 =.125m
f=12.5cm (this is the combined focal length)
!/f=1/f1+1/f2
1/12.5 -1/20 =1/f2
20-12.5/12.5*20
1/f2 = 7.5/250
f2=250/7.5
f2 =33.33cm
so the focal length of the second lens is 33.33cm.
P=1/f f=1/P
f= 1/8 =.125m
f=12.5cm (this is the combined focal length)
!/f=1/f1+1/f2
1/12.5 -1/20 =1/f2
20-12.5/12.5*20
1/f2 = 7.5/250
f2=250/7.5
f2 =33.33cm
so the focal length of the second lens is 33.33cm.
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33.33Answer:
Explanation:
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