According to the theory of plate tectonics, what drives the motion of the continents?
a.
earth's strong magnetic field
b. moving magma in the mantle
c. strong winds along the equator
d.
volcanic islands in the ocean
e.
changing ocean currents

B.moving magma in the mantle

Explanation:

The continents have moved over millions of years. This is due to global convection in the earth's mantle. Since new material continuously comes out of the mantle below the oceanic crust. Thus, a force is created that pushes the areas occupied by the continents, displacing them.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .