The focal length of the objective of a compound microscope is \(f_0\) and its distance from the eyepiece is \(L\). The object is placed at a distance \(u\) from the objective. For proper working of the instrument;
(a) \(L < u\)
(b) \(L > u\)
(c) \(f_0 < L < 2f_0\)
(d) \(L > 2f_0\)

Choose the correct option:
1. (a) and (b)
2. (b) and (d)
3. (b) and (c)
4. (c) and (d)

The angular dispersion produced by a prism:

If a glass prism is dipped in water, its dispersive power:
1. increases
2. decreases
3. does not change
4. may increase or decrease depending on whether the angle of the prism is less than or greater than \(60°\)

A prism can produce a minimum deviation \(\delta\) in a light beam. If three such prisms are combined, the minimum deviation that can be produced in this beam is:
1. 0
2. \(\delta\)
3. 2\(\delta\)
4. 3\(\delta\)

The focal lengths of converging lens are \(f_v\) and \(f_r\) for violet and red light respectively. Choose the correct option:
1. \(f_v > f_r\)
2. \(f_v = f_r\)
3. \(f_v < f_r\)
4. Any of the three is possible depending on the value of the average refractive index \(\mu\)

A narrow beam of white light goes through a slab having parallel faces.
(a) The light never splits in different colours
(b) The emergent beam is white
(c) The light inside the slab is split into different colours
(d) The light inside the slab is white

Choose the correct option:
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (a) and (d)

By properly combining two prisms made of different materials, it is possible to;
(a) have dispersion without average deviation
(b) have deviation without dispersion
(c) have both dispersion and average deviation
(d) have neither dispersion nor average deviation

Choose the correct option:
1. (a) and (b)
2. (b) and (c)
3. (a), (b) and (c)
4. (b), (c) and (d)

In producing a pure spectrum, the incident light is passed through a narrow slit placed in the focal plane of an achromatic lens because a narrow slit:
1. produces less diffraction
2. increases intensity
3. allows only one colour at a time
4. allows a more parallel beam when it passes through the lens

Which of the following quantities related to a lens depend on the wavelength or wavelengths of the incident light?
(a) Power
(b) Focal length
(c) Chromatic aberration
(d) Radii of curvature

Choose the correct option:
1. (a), (b) and (c)
2. (b), (c) and (d)
3. (a) and (b)
4. All of the above

Which of the following quantities increase when wavelength is increased? Consider only the magnitudes.
(a) The power of a converging lens
(b) The focal length of a converging lens
(c) The power of a diverging lens
(d) The focal length of a diverging lens

Choose the correct option:
1. (a) and (b)
2. (b) and (c)
3. (b) and (d)
4. (c) and (d)