PARAGON CONVENT SCHOOL SECTOR – 24 B , CHANDIGARH CLASS – VI ( GEOGRAPHY ) CHAPTER – 3 MOTIONS OF THE EARTH TEXTBOOK WORK *MCQs (Page no – 129) 1. C 2. A *MCQs (Page no – 131) 1. B 2. B *MCQs (Page no – 131) 1. A 2. C *MCQs (Page no – 133) 1. B 2. B EXERCISE *MCQs 1. B 2. C *FILL IN THE BLANKS 1. A leap year has 366 days. 2. The revolution of the Earth causes the cycle of the seasons. 3. The path along which the Earth revolves around the Sun is called orbit. 4. Nicolaus Copernicus proved that the Earth spins on its own axis. *TRUE / FALSE 1. True 2. True 3. False 4. False ANSWER THE FOLLOWING *MCQs 1. A 2. C NOTEBOOK WORK *DIFFERENTIATE BETWEEN THE FOLLOWING 1. spring equinox and autumnal equinox Spring Equinox 1) It occurs on March 21 when rays of the Sun fall vertically on the Equator. 2) At this position, neither of the poles are tilted towards the Autumnal Equinox 1) It occurs on September 23 when rays of the Sun fall vertically on the Equator. 2) At this position, neither of the poles is tilted towards the Sun , resulting in equal days and nights at all places on the Earth. 3) During this period the Northern Hemisphere experiences spring season, while it is the autumn season in the Southern Hemisphere. Sun resulting in equal days and nights at all places on the Earth. 3) During this period , the Northern Hemisphere experiences the autumn season, while it is the spring season in the Southern Hemisphere. 2. perihelion and aphelion Ans. Perihelion :- Around January 4 , when the Earth reaches a point in its orbit where the distance between the Earth and the Sun is the minimum ( about 146 Million Km ) , then we say the Earth is in Perihelion. Aphelion :- Around July 4 , when the Earth reaches a point in its orbit where the distance between the Earth and the Sun is maximum ( around 151 Million Km, then we say the Earth is in Aphelion. *SHORT ANSWER QUESTIONS 1. Define a leap year. Ans. The year in which February is of 29 days instead of 28 days is called a leap year. Thus , a leap year is of 366 days instead of 365 days. 2. What do you understand by the ‘circle of illumination ' ? Ans. The ‘circle of illumination ' is the imaginary line that separates lighted part of the Earth ( where it is day time ) from the dark areas ( where it is night time ). 3. List two factors responsible for the phenomenon of seasons. Ans. The two factors responsible for the phenomenon of seasons are : a) The inclination of the Earth’s axis at a fixed angle and direction. b) The revolution of the Earth around the Sun 4. Why do the places near the Equator have equal days and nights ? Ans. On the places near the Equator , the Sun shines vertically throughout the year, so they have equal days and nights. *LONG ANSWERS QUESTIONS 1. What is rotation ? Discuss it’s effects. Ans. Rotation is the movement of the Earth on its own axis. Its effects are : a) It causes day and night. A day consists of 24 hours. b) The concept of direction based on sunrise and sunset is due to the apparent movement of the Earth. c) Bulging of the Earth at the Equator and flattening at the poles are caused due to rotation. d) Movement of winds , oceans , currents and tides are also caused due to it. 2. What is revolution ? Write down its effects. Ans. Revolution is the movement of the Earth on an inclined axis around the Sun. Its effects are : a) It causes the cycle of seasons. b) It causes the difference in the duration of day and night. c) It is responsible for the difference in distribution of heat over the surface of the Earth. 3. Define the Earth’s orbit and explain the inclination of the Earth’s axis. Ans. Earth’s orbit is the fixed path on which it moves around the Sun. The Earth’s axis is neither perpendicular to the direction of the Sun’s rays nor to the plane of the Earth’s orbit. It is inclined from the vertical line at an angle of 23 ½° . It makes an angle of 66 ½° with its orbital plane which is formed by the orbit of the Earth around the Sun. The Earth always remains tilted to one side while moving around the Sun. This tilt is called the ‘inclination of the Earth’s axis '. 4. What are solstices ? Explain the winter and summer solstices. Ans. Solstices are the position of the Earth when the midday Sun shines vertically overhead at the Tropic of Cancer or the Tropic of Capricorn and the duration of the day is the longest in the hemisphere. a) Winter Solstice occurs on 22 December when the sun’s rays fall vertically over the Tropic of