$A$ small telescope has an objective lens of focal length $140 \ cm$ and an eyepiece of focal length $5 \ cm$. The magnifying power of the telescope for viewing a distant object when the telescope is in normal adjustment is . . . . . . .

$A$ small telescope has an objective of focal length $140 \ cm$ and an eyepiece of focal length $5.0 \ cm$. The magnifying power of the telescope for viewing a distant object is:

In a Galilean telescope,the final image formed is:

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.......$^o$

An opera glass (Galilean telescope) measures $9 \, cm$ from the objective to the eyepiece. The focal length of the objective is $15 \, cm$. Its magnifying power is

All of the following statements are correct except: