A person A can clearly see objects between 25 cm and 200 cm. Which of the following may represent the range of clear vision for a person B having muscles stronger than A, but all other parameters of eye identical to that of A?
1. 25 cm to 200 cm
2. 18 cm to 200 cm
3. 25 cm to 300 cm
4. 18 cm to 300 cm
The focal length of a normal eye-lens is about
1. 1 mm
2. 2 cm
3. 25 cm
4. 1 m
The distance of the eye lens from the retina is \(x.\) For a normal eye, the maximum focal length of the eye lens
1. \(=x\)
2. \(<x\)
3. \(>x\)
4. \(=2x\)
A man wearing glasses of focal length +1m cannot clearly see beyond 1 m
1. if he is farsighted
2. if he is nearsighted
3. if his vision is normal
4. in each of these cases
An object is placed at a distance \(u\) from a simple microscope of focal length \(f.\) The angular magnification obtained depends:
| 1. | on \(f\) but not on \(u\) |
| 2. | on \(u\) but not on \(f\) |
| 3. | on \(f\) as well as \(u\) |
| 4. | neither on \(f\) nor on \(u\) |
To increase the angular magnification of a simple microscope, one should increase:
| 1. | the focal length of the lens | 2. | the power of the lens |
| 3. | the aperture of the lens | 4. | the object size |
A man is looking at a small object placed at his near point. Without alternating the position of his eye or the object, he puts a simple microscope of magnifying power \(5 \times\) before his eyes. The angular magnification achieved is:
1. \(5\)
2. \(2.5\)
3. \(1\)
4. \(0.2\)
When we see an object, the image formed on the retina is
(a) real
(b) virtual
(c) erect
(d) inverted
Choose the correct option:
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (a) and (d)
In which of the following the final image is erect?
(a) Simple microscope
(b) Compound microscope
(c) Astronomical telescope
(d) Galilean telescope
Choose the correct option:
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (a) and (d)
The maximum focal length of the eye-lens of a person is greater than its distance from the retina. The eye is:
1. always strained in looking at an object
2. strained for objects at larger distances only
3. strained for objects at short distances only
4. unstrained for all distances