A Cassegrain telescope uses two mirrors as shown in the figure. Such a telescope is built with the mirrors 20 mm apart. If the radius of curvature of the large mirror is 220 mm and the small mirror is 140 mm, where will the final image of an object at infinity be?

1. 315 mm away from the secondary mirror.
2. 315 mm towards the secondary mirror.
3. 313 mm away from the secondary mirror.
4. 313 mm towards the secondary mirror.

A small telescope has an objective lens of a focal length 140 cm and an eyepiece of focal length 5.0 cm. What is the magnifying power of the telescope for viewing distant objects when the telescope is in normal adjustment (i.e., when the final image is at infinity)?

1. 26
2. 32
3. 28
4. 30

An angular magnification (magnifying power) of \(30\mathrm{X}\) is desired using an objective of focal length \(1.25~\text{cm}\) and an eyepiece of focal length \(5~\text{cm}\). The separation between the objective lens and the eyepiece should be:
1. \(11.67~\text{cm}\)
2. \(10.23~\text{cm}\)
3. \(12.21~\text{cm}\)
4. \(13.13~\text{cm}\)

Light incident normally on a plane mirror attached to a galvanometer coil retraces backward as shown in the figure. A current in the coil produces a deflection of 3.5° of the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away? (tan 7 °=0.1228)

1. 15.0 cm
2. 18.4 cm
3. 21.2 cm
4. 12.5 cm

Figure shows a biconvex lens (of refractive index 1.50) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle. The distance of the needle from the lens is measured to be 45.0 cm. The liquid is removed and the experiment is repeated. The new distance is measured to be 30.0 cm. What is the refractive index of the liquid?

1. 1.65
2. 1.51
3. 1.23
4. 1.33

The linear magnification and angular magnification in the microscope have similar magnitude when the image is at a distance is:
1. \(35~\text{cm}\)
2. \(\infty\)
3. \(25~\text{cm}\)
4. none of these

A card sheet divided into squares each of size \(1~\text{mm}^2\) is being viewed at a distance of \(9~\text{cm}\) through a magnifying glass (a converging lens of focal length \(10~\text{cm}\)) held close to the eye. The angular magnification of the lens is:
1. \(3.34\)
2. \(1.55\)
3. \(3.03\)
4. \(2.78\)

A card sheet divided into squares each of size \(1~\text{mm}^{2}\) is being viewed at a distance of \(9~\text{cm}\) through a magnifying glass (a converging lens of focal length \(10~\text{cm}\)) held close to the eye. What is the magnification produced by the lens? 
1. 11
2. 9
3. 10
4. 12
 

A man with normal near point (\(25~\text{cm}\)) reads a book with small print using a magnifying glass: a thin convex lens of focal length \(5~\text{cm}\). What is the ratio of maximum and the minimum angular magnification (magnifying power) possible using the above simple microscope?
1. \(\frac65\)
2. \(\frac56\)
3. \(\frac32\)
4. \(\frac23\)

A man with a normal near point (\(25~\text{cm}\)) reads a book with small print, using a magnifying glass: a thin convex lens of focal length \(5~\text{cm}\). What is the closest distance at which he should keep the lens from the page so that he can read the book when viewing through the magnifying glass?
1. \(3.5~\text{cm}\)
2. \(4.2~\text{cm}\)
3. \(4.9~\text{cm}\)
4. \(5.0~\text{cm}\)