Question

The length of astronomical telescope for a normal adjustment is 2m and magnifying power is 10. Find the focal lengths of objective and the eye piece.

Answer 1

Hey there!!!

Magnifying Power (M.P.) = 10

Let f° be the focal length of objective and fe be the focal length of eye piece.

M.P. = f°/fe = 10
f° = 10fe.........(1)

Now to find the value of f° ,we need to find the value of fe, so using the formula,
L = f° + ue
L = f° + fe = 200
10 fe + fe = 200
fe = 200/11 cm
fe = 2/11 m
The focal length of eye piece is 2/11m

Now plug in the value of fe to the equation (1):

f° = 10fe
f° = 10× 2/11
f° = 20/11 m

Hence the focal length of objective is 20/11m.



Hope it helps....✌

Answer 2

Answer:

Explanation:

length of a telescope fo+fe =2

m=fo/fe

solving this u will get fo=10fe

fe=2/11

fo=20/11