(a) State snell’s law of refraction of light.

(b) When a ray of light travelling in air enters obliquely into a glass slab, it is observed that the light ray emerges parallel to the incident ray but it is shifted sideways slightly . Draw a labelled ray diagram to illustrate it.

A green stemmed rose plant denoted by GG and a brown stemmed rose plant denoted by gg are allowed to undergo a cross with each other.

(a) List your observation regarding

(i) Colour of stem in their F₁ progeny

(ii) Percentage of brown stemmed plants in F₂ progeny if F₁ plants are self pollinated.

(iii) Ratio of GG and Gg in the F₂ progeny.

(b) Based on the findings of this cross, what conclusion can be drawn ?

(a) Classify the following as homologous or analogous pairs:

(i) Broccoli and cabbage

(ii) Ginger and Raddish

(iii) Fore limbs or birds and lizard

(iv) Wings of a bat and wings of a bird

(b) State the main feature that categorises a given pair of organs as homologous and analogous.

(a) With the help of labelled ray diagram show the path followed by a narrow beam of monochromatic light when it passes through a glass prism.

(b) What would happen if this beam is replaced by a narrow beam of white light ?

OR

(a) A person is suffering from both myopia and hypermetropia.

(i) What kind of lenses can correct this defect ?

(ii) How are these lenses prepared ?

(b) A person needs a lens of power + 3D for correcting his near vision and – 3D for correcting his distant vision. Calculate the focal lengths of the lenses required to correct these defects.

Give reasons for the following:

(i) There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid.

(ii) The current carrying solenoid when suspended freely rests along a particular direction.

(iii) The burnt out fuse should be replaced by another fuse of identical rating.