Exercise - Question:
Q1. Answer the following questions briefly.
Ans. The Earth remains tilted to one side while it revolves around the Earth at an angle of 66
(b) Define rotation and revolution.
Ans. Rotation : The movement of the Earth on its own axis is called rotation. The earth takes 24 hours to Complete one rotation. It causes day and night.
Revolution : The movement of the earth around the sun in a fixed orbit is called revolution. The earth takes 365 days and 6 hours to complete one revolution. It causes seasons.
(c) what is a leap year ?
Ans. It is a year when the month of February has 29 days instead of 28 days. Every fourth year is a leap year.
(d) Differentiate between summer and Winter Solstice.
Ans. summer solstice : It is the position of the earth when the Northern Hemisphere has the longest day and the shortest night. It occurs on 21st June. In the Southern Hemisphere, it is winter season at this time. The days are short and the nights are long.
Winter solstice : It is the position of the earth when southern Hemisphere has long days and shorter nights, In the northern Hemisphere, the days are short and the nights are long. It occurs on 22nd December.
(e) What is an equinox ?
Ans. Equinoxes are days when direct rays of the sun fall on equator. At this position neither of the poles are tilted towards the sun, so the whole earth experiences equal nights. It occurs on 21st March and 23rd September.
(f) Why does the southern Hemisphere experiences Winter and summer Solstice in different times than of Northern Hemisphere.
Ans. The seasons in Southern Hemisphere and Northern Hemisphere are exactly the opposite.
(g) Why do the poles experience six months day and six months nights ?
Ans. When the rays of the sun fall directly on the Tropic of Cancer (21st June), the areas near the south pole receive less heat. The North Pole is inclined towards the sun and places beyond the Arctic circle experience continuous daylight. At this time, the southern Hemisphere has the opposite season. The nights are long and areas beyond Antarctic circle remain in continuous night.
Q2. Tick the correct answers.
(a) The movement of the earth around the sun is Known as
(i) Rotation
(ii) Revolution
(iii) Inclination
(b) Direct rays of the sun fall on the equator on
(i) 21st March
(ii) 21st June
(iii) 22nd December
(c) Christmas is celebrated in summer in
(i) Japan
(ii) India
(iii) Australia
(d) Cycle of the seasons is caused due to
(i) Rotation
(ii) Revolution
(iii) Gravitation
Ans. (a) (ii), (b) (i), (c) (iii), (d) (ii)
Q3. Fill in the blanks :
(a) A leap year has......... number of days.
(b) The daily motion of the earth is......... .
(c) The earth travels around the sun in........ orbit.
(d) The sun's rays fall vertically on the Tropic of........ on 21st June.
(e) Days are shorter during........ season.
Ans. (a) 366, (b) rotation, (c) elliptical, (d) cancer, (e) winter.
