Choose the correct mirror image of the figure:
1. | 2. | ||
3. | 4. |
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 |
An air bubble in a glass slab with refractive index 1.5 (near-normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is:
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 |
A ray of light is incident at an angle of incidence, i, on one face of a prism of angle A (assumed to be small) and emerges normally from the opposite face. If the refractive index of the prism is , the angle of incidence i is nearly equal to:
1. | \(\mu \mathrm{A} \) | 2. | \(\frac{\mu A}{2} \) |
3. | \(A / \mu \) | 4. | \(A / 2 \mu\) |
A concave mirror of the focal length is placed at a distance of d from a convex lens of focal length . 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.
2.
3.
4.
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 cm, 10 cm
2. 15 cm, 5 cm
3. 18 cm, 2 cm
4. 11 cm, 9 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.