Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth?
Stars at a distance of millions of kilometers from the earth. Thus, there large distance are expressed in the light year. One light year is the distance travelled in one year.
One light year = 9.46 x 1012 km.
If a star is located eight years away from the earth that means the distance between the star and the earth is equal to the distance which is travelled by light in eight years. So, the distance between the star and the earth us given by:
8 x (9.46 x 1012) km = 7.6 x 1012 km.
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.
Write a paragraph in your own words on each of the following.
(a) Preparation of soil (b) Sowing
(c) Weeding (d) Threshing
Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.
Name three liquids, which when tested in the manner shown in Fig.14.9, may cause the magnetic needle to deflect.
What is menstruation? Explain.
Explain how soil gets affected by the continuous plantation of crops in a field.
Does pure water conduct electricity? If not, what can we do to make it conducting?
Fill in the blanks:
(a) The planet which is farthest from the Sun is ____________ .
(b) The planet which appears reddish in colour is ____________ .
(c) A group of stars that appear to form a pattern in the sky is known as a ____________ .
(d) A celestial body that revolves around a planet is known as __________.
(e) Shooting stars are actually not ____________.
(f) Asteroids are found between the orbits of _________ and _________ .
What will happen if:
(a) we go on cutting trees.
(b) the habitat of an animal is disturbed.
(c) the top layer of soil is exposed.
Draw sketches to show the relative positions of prominent stars in
(a) Ursa Major and (b) Orion
Name the largest planet of the solar system.