Power of combination of lenses A nd B is 5D. If the focal length of lens A is o.15 find the power and focal lenght of lens B

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Solution

Focal length of A is, F = 0.15 m
Suppose focal length of B is F'.
Now,the power of the combination of lenses=5D
P = 1/F + 1/F'
=> 5 = 1/0.15 + 1/F'

=> F' = -0.6 m ( it is a concave lens)

Thus, lens B is a concave lens of focal length 60 cm and power -1.67 D.

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Power of combination of lenses A nd B is 5D. If the focal length of lens A is o.15 find the power and focal lenght of lens B

Focal length of A is, F = 0.15 m Suppose focal length of B is F'. Now,the power of the combination of lenses=5D P = 1/F + 1/F' => 5 = 1/0.15 + 1/F' => F' = -0.6 m ( it is a concave lens) Thus, lens B is a concave lens of focal length 60 cm and power -1.67 D.

Focal length of A is, F = 0.15 m
Suppose focal length of B is F'.
Now,the power of the combination of lenses=5D
P = 1/F + 1/F'
=> 5 = 1/0.15 + 1/F'

=> F' = -0.6 m ( it is a concave lens)

Thus, lens B is a concave lens of focal length 60 cm and power -1.67 D.