solar question answer

Our Solar System

D1.Name the hottest planet in our solar system.Is it closest to the sun?

Ans: Venus is the hottest planet in our solar system.No venus is not the closest planet to sun.

D2.How much time does the earth take to

(i)                            Revolve once around the sun

(ii)                          to complete one rotation about its own axis.

Ans;(i) earth takes  365 days and 6 hours to revolve once around the sun.

(ii)Earth takes 23 hours 56 minutes to complete one rotation about  its own axis.

D3.State the nature of the shape of orbit of planets.

Ans;The shape of orbit of planets is elliptical.

D4.Write  the meaning  of the Artificial satellites.

Ans:Artificial satellites are the man  made objects which can be made to revolve around  the earth  to perform various task.

E1. How is sun useful to us?

Ans;Sun is useful to us in following ways:

i)It is ultimate source of energy .

ii)  It gives us heat and light

iii) Plant prepare food by using  sunlight in the process of photosynthesis.

iv) sun is essential for growth and maintainance  of all forms of life on earth.

v)Solar energy can be used in solar cooker,solar geyser,calculator.sattelite and many other things.

E2. Name the terrestrial planets .Why are they so called?

Ans:Mercury,venus and earth and mars are  called terrestrial planet. They are called as terrestrial planet because they are made of mainly rocks and metal.

E3.State the conditions necessary  for existence of life on a  planet?

Ans:The conditions necessary   for existence  of life on a planet  are:

i)                   Presence of atmosphere

ii)                Presence of liquid (water)

iii)              Right   size and right distance from sun.

E4.Why do we observe phases of moon?

Ans:We observe the phases of moon due to the changes in the relative position  of earth and the moon with respect  to sun