Question

The defective eye of a person has near point 0.5m and 3m. The power far corrective
lens required for reading purpose and seeing distant objects respectively
a) 0.5D and 3D b) +2D and -1/3D C) -2D and +1/3D d) 0.5D and -3D
2. The air layer of atmosphere whose temperature is less than the hot layer behave as
optically
a) denser medium b) rarer medium c) inactive medium d) either denser or rarer
3. One cannot see through the fog, because
a) refractive index of the fog is very high b) light suffers total reflection at droplets
c) fog absorbs light d) light is scattered by the droplets.
4. A prism ABC(with base BC) is placed in different orientations. A narrow beam of the
prism is shown in figure. In which of the following cases, after dispersion the third
colour from the top corresponds to the colour of the sky.
20)
() (m)
(b) (
(d) (rv)
B
5. The focal length of eye lens increases when eye muscles
a) are relazed and lens becomes thinner b) contract and lens become thicker
c) are relaxed and lens becomes thicker d) contract and lens becomes thinner
6. A person cannot see distinctly objects kept beyond 2m. This defect can be corrected
by using a lens of power
a) -0.50 -0.5D C+0.2D d)-0.2D
7. The blush colour of water in deep sea is due to
al presence of algae and other aquatic plants b) reflection of sky in water
cl scattering of light d) absorption of light by the sea
S. The persistence of vision for human eye is
a 1/10 of a second b) 1/16 of a second c 1/6
of second d) 1/4 of second
9 Two convex lenses of focal length 10cm and 20cm are kept in contact The focal
length of the combination is
a) 20/3cm 6 40cm cl 12cm di 15cm​

Answer 1

Answer:

ABC All the above option are correct and I know the desorption may be correct or may not be so please mark me as a brain list