Determine the direction of the force (if any) that will act on the charge in each of the following situations. a positive charge within an electric field that points to the left. a negative charge within an electric field that points upward. a positive charge moving into the screen in a magnetic field that points upward. a negative charge moving to the left in a magnetic field that points into the screen. a positive charge moving upward in an electric field that points out of the screen. a positive charge moving downward in a magnetic field that points upward.

-force  left  - force down,  - force the right  - force up  -force exiting screen  -force ZERO

Explanation:

The force for the electric and magnetic fields is given by the equations

       F = q E            (1)

       F = q v x B      (2)

Let's analyze each situation

- Positive charge electric field on the left. From equation 1, we see that the force goes to the left

- Negative charge electric field up, force down,

- Positive charge move towards the magnetic field screen up, we apply the law of the right hand, force the right

- Negative charge move left magnetic field towards the screen force up

- Positive charge moves up electric field exiting screen, force exiting screen

- Positive charge moves magnetic field down, force ZERO speed and parallel field

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 .