Spring tides, the highest tides of the month, occur when:
- A.The sun, the earth and the moon are in a straight line
- B.The sun and the moon are at right angles with respect to the earth
- C.The moon is farthest from the earth
- D.The season of spring begins in the northern hemisphere
Correct answer
Explanation
The correct answer is A. Spring tides occur at new moon and at full moon, when the sun, the earth and the moon lie in a straight line, a position called syzygy. The gravitational pulls of the sun and the moon then act along the same line and reinforce each other, so the high tides are unusually high and the low tides unusually low. Spring tides therefore come twice in a lunar month.
Option B describes the position at the first and third quarter, called quadrature, when the two pulls partly cancel and produce the weakest tides of the month, the neap tides. Option C, the moon at apogee, makes tides slightly weaker rather than stronger, since the moon's pull falls off with distance. Option D is the common trap: the word spring here means to leap up, and the tide has nothing to do with the spring season.
Read the full article: Oceans and Ocean Currents: Tides, Salinity and PYQs
Practice Questions
View allWhich of the following ocean currents is associated with the Indian Ocean?
- A.Florida current
- B.Canary current
- C.Agulhas current
- D.Kurile current
Show answer
It is a warm current of the Indian Ocean that flows southward along the eastern coast of southern Africa, carrying tropical water towards the Cape before most of it turns back into the Indian Ocean.
Read the full explanation →El Nino is a name given to the periodic development of a warm ocean current along the coast of _______.
- A.Columbia
- B.Peru
- C.Chile
- D.Bolivia
Show answer
El Nino, Spanish for the child, is the warm surface water that appears off the coast of Peru and Ecuador around Christmas in some years, replacing the normally cold Peru or Humboldt current.
Read the full explanation →With which of the following oceans would you associate the 'Ring of Fire'?
- A.Pacific
- B.Indian
- C.Atlantic
- D.Arctic
Show answer
The Ring of Fire is a horseshoe-shaped belt running around the rim of the Pacific Ocean, from the Andes up the west coast of the Americas, across the Aleutians and down through Japan, the Philippines and Indonesia to New Zealand.
Read the full explanation →The percentage of earth's water found in the oceans is ______.
- A.94 percent
- B.97.2 percent
- C.90.2 percent
- D.92.2 percent
Show answer
Textbooks describing the distribution of water on earth give about 97.2 per cent as ocean water, roughly 2 per cent locked in ice caps and glaciers, and well under 1 per cent as groundwater, lakes, rivers, soil moisture and water vapour together.
Read the full explanation →The highest tidal range in the world is recorded at which of the following?
- A.Gulf of Mexico
- B.Bay of Fundy
- C.Persian Gulf
- D.Gulf of Aden
Show answer
The bay narrows and shallows inland, so the incoming tidal wave is funnelled into a smaller and smaller cross-section and its height is greatly magnified, giving the greatest difference between high and low water anywhere on earth.
Read the full explanation →