The position of the earth when it is nearest to the sun, about 3 January every year, is called:
- A.Aphelion
- B.Perihelion
- C.Equinox
- D.Solstice
Correct answer
Explanation
The correct answer is B, perihelion. The earth's orbit is an ellipse, so its distance from the sun changes through the year; at perihelion, about 3 January, the earth is nearest the sun, which is why the northern winter half of the year is slightly shorter than the summer half. Option A is wrong because aphelion is the opposite position, about 4 July, when the earth is farthest from the sun. Option C is wrong because an equinox, about 21 March and 23 September, is a date on which the sun is vertically overhead at the equator and day and night are equal everywhere, which has nothing to do with distance. Option D is wrong because a solstice, about 21 June and 22 December, is the date on which the sun is vertically overhead at a tropic and the day is longest in one hemisphere.
Read the full article: Geographical Terms and Isolines: Isobar to Isohyet
Practice Questions
View allLines drawn on a map joining places that receive equal amounts of rainfall are called:
- A.Isobars
- B.Isohyets
- C.Isohels
- D.Isotherms
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The word comes from the Greek hyetos, meaning rain, so an isohyet joins all places on a map that receive the same amount of rainfall in a given period; rainfall distribution maps of India, which show the 200 centimetre and 50 centimetre lines, are drawn with isohyets.
Read the full explanation →An isohel is a line on a map joining places having equal:
- A.Cloudiness
- B.Duration of sunshine
- C.Humidity
- D.Salinity
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An isohel, from the Greek helios for the sun, joins places that receive sunshine for an equal number of hours, and such maps are used in studies of solar energy potential and of crop seasons.
Read the full explanation →Lines joining points of equal depth of water in an ocean or a lake are known as:
- A.Isobars
- B.Isobaths
- C.Isopachs
- D.Isohypses
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The Greek bathos means depth, so isobaths are the depth contours of a bathymetric chart; the 200 metre isobath is conventionally taken as the outer edge of the continental shelf.
Read the full explanation →Isoseismal lines on a map are drawn to show equal:
- A.Intensity of an earthquake
- B.Thickness of rock strata
- C.Travel time from a place
- D.Wind speed
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Isoseismal lines join points at which the shaking of an earthquake was felt with the same intensity, and because intensity falls away from the source, they are drawn as roughly concentric closed curves around the epicentre, the point of the surface vertically above the focus.
Read the full explanation →The line joining places where the magnetic declination is zero is called the:
- A.Isogonic line
- B.Agonic line
- C.Isoclinic line
- D.Aclinic line
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Magnetic declination is the angle between true north and magnetic north, and along the agonic line that angle is zero, so a compass needle there points to true north.
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