Question

two thin lenses of power + 3.5 diopter and -2.5 diopter are placed in contact find power of combination and focal length of the combination

Answer 1

Hey here is your answer
___________________
P1= 3.5
P2=-2.5

Peq= p1 + p2
=3.5+(-2.5)
=3.5-2.5
=1 D

Focal length =1/p
=100/100cm
=1cm

Answer 2

Answer:

+100

Explanation:

combine power=P1+P2

                          =3.5+(-2.5)

                          =1D

1D =1m

D=1/f

1=1/f

f=1/1

f=1m or 100cm

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