If a telescope is reversed,i.e.,viewed from the objective side,what happens to the appearance of the object?

$(a)$ $A$ small telescope has an objective lens of focal length $140\;cm$ and an eyepiece of focal length $5.0\;cm$. What is the separation between the objective lens and the eyepiece?
$(b)$ If this telescope is used to view a $100\;m$ tall tower $3\;km$ away,what is the height of the image of the tower formed by the objective lens?
$(c)$ What is the height of the final image of the tower if it is formed at $25\;cm$?

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement-$1$: Very large size telescopes are reflecting telescopes instead of refracting telescopes.
Statement-$2$: It is easier to provide mechanical support to large size mirrors than large size lenses.

What is a telescope? Discuss the types of telescopes that are used in general.

An astronomical telescope has an angular magnification of magnitude $5$ for distant objects. The separation between the objective and the eyepiece is $36 \, cm$. The final image is formed at infinity. The focal length $f_o$ of the objective and $f_e$ of the eyepiece are

To increase the magnifying power of a telescope ($f_o$ = focal length of the objective and $f_e$ = focal length of the eye lens):