In an astronomical telescope, the focal length of the objective lens is \(100\) cm and of the eyepiece is \(2\) cm. The magnifying power of the telescope for the normal eye is:
1. \(50\)
2. \(10\)
3. \(100\)
4. \(\frac{1}{50}\)

The magnifying power of a telescope is \(9\). When it is adjusted for parallel rays the distance between the objective and eyepiece is \(20\) cm. The focal lengths of lenses are:
1. \(10~\text{cm}, 10~\text{cm}\)
2. \(15~\text{cm}, 5~\text{cm}\)
3. \(18~\text{cm}, 2~\text{cm}\)
4. \(11~\text{cm}, 9~\text{cm}\)

To increase the magnifying power of a telescope:

An astronomical telescope has angular magnification of \(20\) in its normal adjustment. Focal length of eyepiece is \(4\) cm. Distance between objective and eyepiece is:
1. \(80\) cm
2. \(84\) cm
3. \(76\) cm
4. \(90\) cm

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. \(10~\text{cm}, 190~\text{cm}\)

An astronomical telescope has angular magnification of \(40\) in its normal adjustment. If focal length of eyepiece is \(5\) cm, the length of the telescope is:
1. \(190\) cm
2. \(200\) cm
3. \(205\) cm
4. \(210\) cm

The minimum magnifying power of an astronomical telescope is \(40\). If the length of the telescope is \(205\) cm, then the focal length of its field lens is:
1. \(5\) cm
2. \(200\) cm
3. \(40\) cm
4. \(140\) cm