Class Notes NCERT Solutions for CBSE Students
Question: What is a leap year?
Answer: One revolution takes 365 1/4 days 1/4 day is equal to 6 hours. We take 365 days as a single year and the 1/4 day of four consecutive years is added to the month of February in the fourth year. Thus, every fourth year ( in a group of four consecutive years ) has 366 days. Such a year is called a leap year.
Question: Why does the duration of day and night vary?
Answer: It varies because of the change in seasons, during the summer, days are longer and nights are shorter and during winters, days are shorter and nights are longer.
Question: What is an equinox?
Answer: The term ‘equi’ means equal and ‘nox’ means night together they mean the day when night and day are of equal duration ( 12 hours each ) One of the two days in a year. When the direct rays of the sun fall on the equator causing equal day and night all over the globe.
Question: What causes seasons?
Answer: The revolution of earth around the sun and the till of the earth causes.
Question: What is the plane of the earth’s orbit?
Answer: Level path on which the earth revolves around the sun.
Question: How seasons are caused?
Answer: The revolution of the earth around the sun and tilt of its axis cause the change in seasons. When North Pole tilt towards the sun the direct rays of the sun falls on the tropic of Cancer 23 1/2° N this position of the earth is called summer solstice. Hence the northern hemisphere has the summer season and the southern hemisphere experience winter.
When the south pole is tilted towards the sun and the overhead rays of the sun are now falling on the tropic of Capricorn, this position is called winter, Solstice, Hence, the southern hemisphere experience the summer seasons and northern hemisphere experience winter season.
