Something to Know
A. Fill in the blanks.
1. The earth is sometimes known as the blue planet.
2. The earth completes one rotation about its axis in 24 hours.
3. The main members of the solar system are the sun and eight planets.
4. The sun is a huge source of heat and light.
5. Day and night occur on earth due to its rotation about its own axis.
B. Match the following:
1. the ringed planet e. Saturn
2. the largest planet c. Jupiter
3. a natural satellite d. Moon
4. the windy planet b. Neptune
5. the smallest planet a. Mercury
C. Tick (✔) the correct option.
1. The number of planets, in our solar system, is-
(a) seven
(c) nine
(b) eight (✔)
(d) ten
Answer – (b) eight (✔)
2. The planet, which reflects large amount of sunlight falling on it, is-
(a) Mercury
(b) Mars
(c) Earth
(d) Venus (✔)
Answer – (d) Venus (✔)
3. The planet Uranus is also known as a-
(a) windy planet
(b) terrestrial planet
(c) jovian planet (✔)
(d) red planet
Answer – (c) jovian planet (✔)
4. The correct statement, about the atmosphere of the planet named in it, is-
(a) Venus has mostly carbon dioxide around it. (✔)
(b) Mercury has mostly nitrogen around it.
(c) Saturn has mostly helium around it.
(d) Earth has mostly ozone around it.
Answer – (a) Venus has mostly carbon dioxide around it. (✔)
5. The fourth and the sixth planets, of the solar system, are, respectively-
(a) Jupiter and Uranus
(c) Uranus and Jupiter
(b) Mars and Saturn (✔)
(d) Neptune and Saturn.
Answer -(b) Mars and Saturn (✔)
6. Consider the following statements about the Earth’s moon:
A. The moon is Earth’s natural satellite.
B. We can see full moon after every 15 days.
C. The moon is a non-luminous object.
D. The moon takes nearly 18 days to complete one revolution around the earth.
The statements, that are correct, are the statements-
(a) A and B
(b) B and D
(c) B and C
(d) A and C
Answer – (d) A and C (✔)
7. The first Indian satellite is-
(a) Kalpana-1
(b) Aryabhatta (✔)
(c) INSAT
(d) EDUSAT
Answer -(b) Aryabhatta (✔)
D. Answer the following questions in brief.
1. Name the hottest planet in our solar system. Is it closest to the Sun?
Answer – The hottest planet in our solar system is Venus. It is not closest to the sun.
2. How much time does the earth take to-
(i) Revolve once around the sun?
Answer – 365 days and 6 hours.
(ii) To complete one rotation about its own axis?
Answer – 24 hours
3. State the nature of the shape of orbit of planets.
Answer – The orbits of planets are elliptical in shape.
4. Write the meaning of the term ‘Artificial Satellites’.
Answer – Artificial satellites are the men made satellites which are made to revolve around the earth.
E. Answer the following questions.
1. How is the sun useful to us?
Answer – Sun is useful to us in following ways:
(i) It gives us heat and light energy.
(ii)Plants prepare food by using sunlight and all animals including us get food directly or indirectly from plants.
(iii)We use solar energy to run devices like solar geysers, solar cookers, calculators, etc.
2. Name the terrestrial planets. Why are they so called?
Answer – The terrestrial planets are Mercury, Venus, Earth and Mars. They are so called because they are made up of rocks and metal.
3. State the conditions necessary for existence of life on a planet.
Answer – The conditions necessary for existence of life on a planet are:
Presence of atmosphere.
Presence of liquid water on the surface.
Right size and right distance from the sun that enables it to receive just the correct amount of solar energy.
4. Why do we observe phases of moon?
Answer – We observe phases of the moon because of the changes in the relative position of the earth and the moon, with respect to the sun.
5. State two uses to which artificial satellites are being put.
Answer – The two uses to which artificial satellites are being put are:
They are used in communication for transmitting radio, telephone and television signals.
They are used for weather forecasting and remote sensing.
Value Based Question
The students of Class-V, of the local DAV school, were invited by the boss of a new industrial unit.
The students, and teachers, of the school felt very happy when they visited this new industrial unit. The boss and staff, of the unit, greeted them warmly and took them around their unit.
They told their visitors that their UNIT was very eco-friendly and was using solar panels (assembly of Solar Cells) to meet most of their energy requirements.
1. State the values displayed by the boss and staff of the industrial unit.
Answer – The values displayed by the boss and staff of the industrial unit are polite, eco-friendly, enthusiastic.
2. Do you think that it is advisable to use solar panels whenever, and wherever, possible?
Answer – No, it is not advisable to use solar panels whenever and wherever possible because solar energy cannot be used during night and cloudy weather. It is little costly too.
Something to Do
1. Make your own scrapbook of solar system by collecting data about sizes, distances, temperatures, etc., of its members.
Answer – Students will do this task at their own accord.
2. Observe the moon continuously for several nights. Make a sketch of moon every night. Try to find the time interval between full moon and new moon.
Answer – Students will do this task at their own accord.
3. Try to make a Model of the Sun, Earth and Moon that shows the Earth orbiting the Sun, and the Moon moving around the Earth.
Answer – Students will do this task at their own accord.
4. Try to make riddles on ‘Planets.’ One example is given below:
I am a planet very close to the sun. I appear to be a tiny planet which is very hot. I have no moons but I orbit the sun very fast. Can you guess my name?
(Ans. Mercury)
Answer – Students will do this task at their own accord.
By Sunaina Karmakar