Chapter 5 - Temperature
(A) Where am I?
(1) The isotherm 0°C runs in my surroundings.
Ans: I must be in polar region
(2) The mean annual temperature is 25°C around me.
Ans: I must be in tropical region
(3) The mean annual temperature around me is 10°C.
Ans: I must be in temperate region
(B) Who am I?
(1) I connect places of equal temperature.
Ans: Isotherm
(2) I am useful for measuring the correct temperature.
Ans: Thermometer
(3) I get heated due to the land or water near me.
Ans: Air
(4) Land and water get heated due to me.
Ans: Sun
(C) Answer the following.
(1) Explain with a diagram, the effect of the spherical shape of the earth on the temperature at different latitudes.
Ans:
(i) Due to the curvature of the earth, sun rays falling from the sun occupy larger areas at some places and smaller areas at others.
(ii) Due to this uneven distribution of sun’s heat, there is a temperature difference between the Equator; and the North and South Poles.
(iii) Based on the distribution of temperature, the earth can be divided into torrid, temperate and frigid zones.
(a) Torrid zone: Between 0⁰ and 23⁰ 30′ North and South, the sun rays are perpendicular. Hence this area receives bright sunlight and greater heat.
(b) Temperate Zone: It lies in between 23⁰ 30′ and 66⁰ 30′ North and South, the sunrays are slanting. Hence these areas receive less bright sunlight and less heat.
(c) Frigid zone: Between 66⁰ 30′ and 90⁰ North and South, the sunrays are extremely slanting. Hence these areas receive extremely less bright sunlight and extremely less heat.
(2) What is the relation between the latitudinal extent and temperature of a region?
Ans:
(i) Due to the curvature of the earth, sun rays falling from the sun occupy larger areas at some places and smaller areas at others.
(ii) Due to this uneven distribution of sun’s heat, there is a temperature difference between the Equator; and the North and South Poles.
(iii) Between 0⁰ and 23⁰ 30′ North and South, the sun rays are perpendicular. Hence this area receives bright sunlight and greater heat.
(iv) Between 23⁰ 30′ and 66⁰ 30′ North and South, the sunrays are slanting. Hence these areas receive less bright sunlight and less heat.
(v) Between 66⁰ 30′ and 90⁰ North and South, the sunrays are extremely slanting. Hence these areas receive extremely less bright sunlight and extremely less heat.
(3) What makes the isotherms run zigzag over continental areas?
Ans:
(i) Temperatures of continental areas vary as per their height from the sea level. As one moves higher up from the surface of continental areas, the temperature decreases.
(ii) Due to the difference in the height of the continental areas, the distance between the isotherms varies.
(iii) Vegetation cover, urbanization, Industrialization also leads to diversity in the distribution of temperature.
(iv) Thus, these factors also make the isotherms run zigzag over continental areas.