A child staying in a coastal region tests the drinking water and also the seawater with his tester. He finds that the compass needle deflects more in the case of seawater. Can you explain the reason?

Describe with the help of a diagram an instrument which can be used to detect a charged body.

Sketch larynx and explain its function in your own words.

Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.

Make a labelled diagram of a candle flame.

What is metamorphosis? Give examples.

The following Table shows the total power shortage in India from 1991– 1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.

Make sketches of animal and plant cells. State three differences between them.

What is a constellation? Name any two constellations.

Describe the construction of a kaleidoscope.

Complete the crossword with the help of clues given below:
Across
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
6. The living substance in the cell.
8. Units of inheritance present on the chromosomes.

Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.

Two mirrors meet at right angles. A ray of light is incident on one at an angle of 30° as shown in Fig. 16.19. Draw the reflected ray from the second mirror.

Explain the process of formation of petroleum.

Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Sulphur dioxide                                                                                                                                                                                                                                  (c) Methane
(d Nitrogen

What is a constellation? Name any two constellations.

Make sketches of animal and plant cells. State three differences between them.

In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.

Complete the word puzzle:
Down
1. Species on the verge of extinction.
2. A book carrying information about endangered species.
5. Consequence of deforestation.
Across
1. Species which have vanished.
3. Species found only in a particular habitat.
4. Variety of plants, animals and microorganisms found in an area.

List sources of noise pollution in your surroundings.

Explain why a charged body loses its charge if we touch it with our hand.

Make a sketch of the human nerve cell. What function do nerve cells perform?