Why does the increased level of nutrient | Class 8 Science Chapter Pollution of Air and Water, Pollution of Air and Water NCERT Solutions

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.

Describe the construction of a kaleidoscope.

What is a constellation? Name any two constellations.

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.

Image formed by a plane mirror is
(a) virtual, behind the mirror and enlarged
(b) virtual, behind the mirror and of the same size as the object
(c) real at the surface of the mirror and enlarged
(d) real, behind the mirror and of the same size as the object.

What is menstruation? Explain.

Explain how fertilisers are different from manure.

Write T against true and F against false in the following statements:
(a) Like charges attract each other (T/F)
(b) A charged glass rod attract a charged plastic straw (T/F)
(c) Lightning conductor cannot protect a building from lightning (T/F)
(d) Earthquakes can be predicted in advance (T/F)

Explain in what way noise pollution is harmful to humans.

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.

Explain why the sliding friction is less than the static friction.

Sometime, a crackling sound is heard while taking off sweater during winters. Explain.

Give two examples each of situations in which you push or pull to change the state of motion of objects.

Why should paper be saved? Prepare a list of ways by which you can save paper.