In normal adjustment, the angular magnification of an astronomical telescope is \(39\). If length of the tube is \(2\) m, then focal length of the objective and eyepiece are respectively:

1.	\(195~\text{cm}, 5~\text{cm}\)	2.	\(190~\text{cm}, 10~\text{cm}\)
3.	\(20~\text{cm}, 180~\text{cm}\)	4.	\(10~\text{cm}, 190~\text{cm}\)

If a light ray is incident normally on face \(AB\) of a prism, then for no emergent ray from second face \(AC\):
\([\mu \rightarrow\) refractive index of glass of prism]

A lens forms an image of a point object placed at distance \(20~\text{cm}\) from it. The image is formed just in front of the object at a distance \(4~\text{cm}\) from the object (and towards the lens). The power of the lens is:
1. \(-2.25~\text D\) 
2. \(1.75~\text D\) 
3. \(-1.25~\text D\) 
4. \(1.4~\text D\) 

The distance between the object and its real image formed by a concave mirror is minimum when the distance of the object from the center of curvature of the mirror is: (where\(f\) is the focal length of the mirror)
1. zero
2. \(\dfrac{f}{2}\)
3. \(f\)
4. \(2f\)

A point object \(O\) is placed at a distance \(20\) cm from a biconvex lens of the radius of curvature \(20\) cm and \(\mu=1.5.\) The final image produced by lens and mirror combination will be at:

A person can see objects clearly between \(1~\text{m} \)and \(3~\text{m}. \). The power of the lens required to correct near point will be:
1. \(-2.5~\text{D}\)
2. \(3~\text{D}\)
3. \(+ 1.5~\text{D}\)
4. \(- 1.75~\text{D}\)

In the case of a compound microscope, the image formed by the objective lens is: