Refraction of Refraction — Science STD 10 — Question

What is meant by rainwater harvesting? Name some of the ancient structures used for rainwater harvesting by the rural people.

What is the position of the image when an object is placed at a distance of 20cm from a concave mirror of focal length 20cm?

Suggest a safe and efficient method for the disposal of biowastes and sewage materials. How is this method advantageous to us?

When a light ray passes from air into glass, what happens to its speed? Draw a diagram to show which way the ray of light bends.

Name the five types of tropisms. How are tropic movements helpful to plants? Explain with an example.

Bio-mass contains stored energy. Justify it.

Why are fuses fitted in the fuse box of a domestic electricity supply?

In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt away and has to be replaced.

1. Which carbon electrode (cathode or anode) is burnt away?
2. Why is this carbon electrode burnt away?

What is meant by ‘unisexual flowers’ and ‘bisexual flowers’ ? Give two examples of each.

Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive:

1. Yellow seed
2. Round seed