The Human Eyes And The Colourful World — Science STD 10 — Question

Write the structure of eye lens and state the role of ciliary museles in the human eye.

Name the main organs of the human digestive system. Also name the associated glands.

Why do plants need nitrogen? How do plants obtain nitrogen?

Name the individual units of floral whorls.

a. State one important function of ozone layer at the higher level in the atmosphere.
b. How is ozone formed?
c. It has been observed that ozone layer is getting depleted. Name the compound responsible for ozone depletion.

What is meant by ‘refraction of light’? Draw a labelled ray diagram to show the refraction of light.

Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray of light parallel to the principal axis of a convex mirror and show the angle of incidence and angle of reflection on it.

It is desired to obtain an erect image of an object, using concave mirror of focal length of 12cm.
Where will the image of this object be, if it is placed 24cm in front of the mirror? Draw ray diagram for this situation also to justify your answer.
Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams.

How much energy is transferred by a 12V power supply to each coulomb of charge which it moves around a circuit?