Question

object?
54) Two convex lenses of focal length 30 c.m and 10 c.m each are kept in contact with
each other. Find the power of their combination.
ane of the lens while seeing distant and​

Answer 1

Given:-

Focal length of 1st convex lens = F1 =30

Focal length of 2nd convex lens = F2 =10

TO FIND:-

POWER OF THEIR COMBINATION = F = ?

FORMULA:-

1/F = 1/F1 + 1/F2

SOLUTION:-

1/F = 1/F1 + 1/F2

1/F = 1/30 + 1/10

1/F = 1+3/30

1/F = 4/30

1/F = 2/15

15 = 2F

15/2 = F

F = 15/2

F = 7.5 CM

NOW,

P = 1/F

P = 1/7.5

P = 10/75

P = 2/15

Answer 2

Step-by-step explanation:

1/F=1/f+1/f

1/F=1//30+1/10

1/F=40/300

F=300/4

F=7.5

P=1/F

P=1/7.5