Answer:
Explanation:
Image formation by objective lens ,
f = focal length of objective = .75 cm, ( positive )
object distance u = .81 cm ( negative )
v = image distance
1/v - 1/u = 1/f
1/v + 1/.81 = 1 / .75
1/v = 1/ .75 - 1/.81 = .098765
v = 10.125.cm
Image formation by eye piece,
v = infinity ( for relaxed eye )
f ( eye piece ) = 2.70cm
u = ?
1/v - 1/u = 1/f
0 -1/u = 1/2.7
u = 2.7 cm
Total length between lenses
= 2.7 + 10.125
= 12.825 cm
Total magnification = m₁ x m₂
m₁ is magnification by objective and m₂ is magnification by eye piece
m₁ = v/u = 10.125 / .810 = 12.5
m₂ = 1 + D / f = 1 + 25 / 2.7 = 10.25
Total magnification
= 12.5 x 10.25 = 128.125
