Question

A convex lens and a concave lens of focal length 25cm and 20cm respectively are in contact. Power of their combination is *
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Answer 1

Answer:

Don't know bro .I can't help you...

Answer 2

Answer:

ple mark the brainlist

Explanation:

Given that

Focal length of a convex lens,F1=20

Focal length of a concave lens,F2=25

power of a convex lens,P1=100/F1

=100/20

=+5D

now,

power of a concave lens,P2=100/25

=-4D

therefore,

i)power of combination,P3=P1+P2

=5+(-4)

=1

ii)focal length of combination=100/P3

=100/1

=100cm

therefore the ans of power of combination and focal length are 1 & 100 cm

Thank you