MODEL QUESTIONS

An astronomical telescope uses two lenses of powers $10 \mathrm{D}$ and $1 \mathrm{D}$. What is magnifying power in normal adjustment?

Correct the following sentence:

The distance of distinct vision for a normal eye is $30 \mathrm{cm}$.

Correct the following sentence:

A person suffering from long-sight can see near objects clearly but not distant objects.

Correct the following sentence:

One of the reasons for short-sight in a person is flattening of the eyeball.

Correct the following sentence:

The objective of telescope has small aperture.

Correct the following sentence:

For a simple microscope with image at infinity the magnifying power $M$ is given as $M = \left(1+D\right)/f$, where $D$ is the distance of distinct vision and $f$ is the focal length of the lens used in simple microscope.

Correct the following sentence:

A person suffering from long sight uses convex lens.

Correct the following sentence:

The distance between objective and eye-piece of an astronomical telescope for normal vision setting is $\left(f_o+f_e\right)/2$.