Why is the distance between stars expres | Class 8 Science Chapter Stars and The Solar System, Stars and The Solar System 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.

Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

In order to meet the ever-increasing demand in factories and for shelter, trees are being continually cut. Is it justified to cut trees for such projects? Discuss and prepare a brief report.

Complete the following word puzzle with the help of clues given below. 

Down
1. Providing water to the crops.
2. Keeping crop grains for a long time under proper conditions.
5. Certain plants of the same kind grown on a large scale.

Across
3. A machine used for cutting the matured crop.
4. A rabi crop that is also one of the pulses.
6. A process of separating the grain from chaff.

When we press the bulb of a dropper with its nozzle kept in water, air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water gets filled in the dropper. The rise of water in the dropper is due to

(a) pressure of water
(b) gravity of the earth
(c) shape of rubber bulb
(d) atmospheric pressure

Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plugs/switches/plug boards

Describe how coal is formed from dead vegetation. What is this process called?

Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?

Describe characteristics and uses of coke.

State the difference between eukaryotes and prokaryotes.

Clear, transparent water is always fit for drinking. Comment.