Control and Coordination — Science STD 10 — Question

Explain why, if we look at objects through the hot air over a fire, the objects appear to be moving (or shaking) slightly.

a. What happens when in a human female the egg released by the ovary is not fertilized?
b. Name one bacterial and one viral infection caused due to unsafe sex.

State the two laws of reflection of light.

What is autonomic nervous system? What is its function?

Write down a formula for the magnification produced by a concave mirror.

1. In terms of height of object and height of image.
2. In terms of object distance and image distance.

How could you find the focal length of a convex lens rapidly but approximately?

Why does the sky appear dark instead of blue to an astronaut?

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.

Why does a new aluminium vessel lose shine so soon after use?

Define "Parasitic nutrition" Give one example of each type.