Are the paths of electrons straight lines between successive collisions( with positive ions of the metal )in the: (i) absence of electric field? (ii) presence of electric field
Hint: The electric field is defined as the force of electricity per unit of charge. The force exerted by the ground on a positive test charge is believed to be in the same direction as the field. The electric field of a positive charge is radially outward, while the field of a negative charge is radially inward.
Complete answer: Only if the direction of the velocity and the electric field are the same at any point along the path is a charged body's path taken under the influence of an electric field a straight line (this also includes the starting point). However, there is no guarantee that the electron will follow a straight path in such random collisions under the influence of a random electric field. Even if you manage to keep the electric field steady and uniform, the electron will almost always follow a parabolic (curved) direction. The motion of the electron would be similar to that of a projectile in this situation. So, from the above gathered data we can conclude that, (i) Absence of electric field: In the absence of an electric field, the paths of free electrons in a metal conductor are straight lines between two consecutive collisions. (ii) Presence of electric field: In the presence of an electric field, the paths of free electrons in a metal conductor are twisted.
Note: The electric field is oriented in the same direction as the force on a positive charge. Because of its negative charge, an electron can pass in the opposite direction of the electric field. As a result, it will shift to the left.