Q. No.
If there had been one eye of a man, then:
| 1. | image of the object would have been inverted |
| 2. | visible region would have decreased |
| 3. | image would have not been seen in three dimensional |
| 4. | Both (2) and (3) |
The near point of a person is 50 cm and the far point is 1.5 m. The spectacles required for reading purposes and for seeing distant objects are respectively:
1. + 2D, \(-\frac{2}{3}~D\)
2. \(+\frac{2}{3}~D\), - 2 D
3. - 2 D, \(+\frac{2}{3}~D\)
4. \(-\frac{2}{3}~D\), + 2 D
An astronomical refracting telescope will have large angular magnification and high angular resolution when it has an objective lens of:
| 1. | Small focal length and large diameter |
| 2. | Large focal length and small diameter |
| 3. | Large focal length and large diameter |
| 4. | Small focal length and small diameter |
| 1. | \(8\) | 2. | \(10\) |
| 3. | \(12\) | 4. | \(16\) |
If the focal length of the objective lens is increased, then magnifying power of:
| 1. | microscope will increase but that of telescope decrease |
| 2. | microscope and telescope both will increase |
| 3. | microscope and telescope both will decrease |
| 4. | microscope will decrease but that of the telescope will increase |
| 1. | \(\mu A \) | 2. | \(\frac{\mu A}{2} \) |
| 3. | \(A / \mu \) | 4. | \(A / 2 \mu\) |
A concave mirror of the focal length \(f_1\) is placed at a distance of \(d\) from a convex lens of focal length \(f_2\). A beam of light coming from infinity and falling on this convex lens-concave mirror combination returns to infinity. The distance \(d\) must be equal to:
1. \(f_1 +f_2\)
2. \(-f_1 +f_2\)
3. \(2f_1 +f_2\)
3. \(-2f_1 +f_2\)
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. | \(11~\text{cm}, 9~\text{cm}\) |
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. | \(\dfrac{1}{50}\) |
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