What is a telescope?

$A$ telescope has an objective of focal length $100 \ cm$ and an eye-piece of focal length $5 \ cm$. The magnifying power of the telescope is

Four convergent lenses have focal lengths $100 \, cm, 10 \, cm, 4 \, cm$ and $0.3 \, cm$. For a telescope with maximum possible magnification,we choose the lenses of focal length

The diameter of the moon is $3.5 \times 10^3 \text{ km}$ and its distance from the earth is $3.8 \times 10^5 \text{ km}$. If it is seen through a telescope whose focal lengths for the objective and eye lens are $4 \text{ m}$ and $10 \text{ cm}$ respectively,then the angle subtended by the moon on the eye will be approximately.......$^o$

Focal length of objective and eye piece of telescope are $200 \; cm$ and $4 \; cm$ respectively. What is the length of telescope for normal adjustment (in $; cm$)?

$A$ Galilean telescope has an objective and an eyepiece of focal lengths $200 \, cm$ and $2 \, cm$ respectively. The magnifying power of the telescope for normal vision is