Life Processes — Science STD 10 — Question

A man standing in front of a special mirror finds his image having a very small head, a fat body and legs of normal size. What is the shape of:

1. Top part of the mirror?
2. Middle part of the mirror?
3. Bottom part of the mirror?

Give reasons for your choice.

State the factors on which the heat produced in a current conductor depends. Give one practical application of this effect.

On cutting the body of an organism into many pieces it was observed that many of these pieces developed as new individuals. Name the process and list two organisms in which this process may be observed. Draw a schematic diagram to illustrate the changes that are likely to be observed during the development of new individuals in any one of the organisms named.

In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.

What is meant by a primary consumer, secondary consumer and a tertiary consumer? Give one example of each.

Find the equivalent resistance across the two ends A and B of the following circuit.

How is zinc extracted from its carbonate ore (calamine)? Explain with equations.

Suggest three contraceptive methods to control the size of human population which is essential for the health and prosperity of a country. State the basic principle involved in each.

How does the resistance of a conductor depend on:

1. Length of the conductor?
2. Area of cross-section of the conductor?
3. Temperature of the conductor?