Agroup of students are studying the magnetic field of earth. which of these layers of earth interact to create earth's magnetic field?

a)crust and core
b)mantle and crust
c)mantle and inner core
d)outer core and inner core

D

Explanation:

The inner core (which is solid) is the hottest layer of the earth. It, therefore, contributes to heating up the outer core. The outer core is liquid and rotation of the earth (Coriolis effect) causes the molten rocks to swirl like a tornado. Because the outer core is mostly made of metals, that have lost electrons and hence charged (due to the enormous heat), the swilring effect causing an electric effect. This consequently causes the dynamo effect that creates a magnetic field. This magnetic field covers the earth and protects it from harmful radiation from the solar storms.  

the tides are influenced by both the moon and the sun, it's easy to see that when the sun lines up with the moon and the earth, as during a new moon or full moon, the tidal effect is increased. these are known as spring tides, named not for the season, but for the fact that the water "springs" higher than normal. on the other hand, if the sun and the moon are 90 degrees apart in relation to an observer on earth as during the first quarter moon or third quarter moon, then high tides are not as high as they normally would be. this is because despite its greater distance, the sun's mass allows it to exert enough gravitational force on the oceans that it can negate some of the effects of the moon's pull. this phenomenon of lower high tides is called a neap tide. if you need more information on this topic visit moonconnection.com.