Question

The length of astronomical telescope is 105 cm and magnification is 20 . Find focal length of objective lens

Answer 1

Explanation:

I=fo+fe=105

20=fo+fe=105

20fe+fe=105

21fe =105

fe=105/21

fe= 5

Focal length:-

fo=20fe

fo=20(5)

fo=100 cm

Hope it will help you

Answer 2

ஜ۩۞۩ஜ ӇЄƳƛ MƛƬЄ ஜ۩۞۩ஜ

Answer....

magnification ,

M = f(o)/f(e)

20 = f(o)/f(e)

f(o) = 20f(e)

length of telescope ,

L = f(o) + f(e)

105 = 21 f(e)

f(e) = 5 cm

so,

f(o) = 100 cm

нσρє нєℓρѕ !❤️❤️