In which of the following is the final image erect?

$A$ microscope has an objective of focal length $1 \ cm$ and an eyepiece of focal length $6 \ cm$. If the tube length is $30 \ cm$ and the image is formed at the least distance of distinct vision,what is the magnification produced by the microscope? Take $D = 25 \ cm$.

For observing a cricket match,a binocular is preferred to a terrestrial telescope because

The focal lengths of the objective and the eyepiece of a compound microscope are $1 \, cm$ and $5 \, cm$ respectively. An object is placed at a distance of $1.1 \, cm$ from the objective. If the final image is formed at infinity,the magnifying power of the microscope is:

In a compound microscope,the objective lens and eyepiece have focal lengths of $0.95 \ cm$ and $5 \ cm$ respectively,and are kept at a distance of $20 \ cm$. The final image is formed at a distance of $25 \ cm$ from the eyepiece. Calculate the magnifying power.

If the tube-length $(L)$ of a compound microscope increases,then its magnification . . . . . . .