<span>When an electric current flows through a long conductor, each free electron moves from one end of the other end. When an electric field is applied to a conductor (a wire) the free electrons of the conductor are subject to an electric force which will cause the electrons to move. Given that the electrons are negatively charged they will move counter-wise the field.. Each end of the wire is attached to one pole or end of a battery (or generator of electricity) then the electrons will move form the end joined to the negative pole toward the end attached to positive pole.</span><span />
Answer: 4550 Joules
The formula for potential energy in gravitational field is as follows:

The electric force between the two particles are calculated through the equation,
F = kQ₁Q₂ / d²
where F is the force, k is a constant called Coulomb's law constant, Q₁ and Q₂ are the charges, and d is the distance. This equation is called the Coulomb's law.
It can be seen from the equation above that the electric forces between the objects are majorly affected by the substance's charges and distance.
The answer to this item is therefore letter A.
Maybe this would help understand it better.
<span>Tectonic plates can transport both continental crust and oceanic crust, or they may be made of only one kind of crust. Oceanic crust is denser than continental crust. At a subduction zone, the oceanic crust usually sinks into the mantle beneath lighter continental crust</span>