Question

Points A and B are in a region of uniform electric field. Point A is at the origin and point B is on the x-axis at x = 0.150 m. The electric potential at point A is 200 v and the electric potential at point B is 500 v. What are the magnitude and direction of the uniform field in this region?

Answer 1

Answer: 2000 v/m, from B to A.

Explanation: if point A is at the origin (x=0m) and point B is at the point x= 0.150m, the distance between both points (d) = 0.150 - 0 = 0.150m

Point A is at a 200v potential and point B is at a potential of 500v.

Difference in potential produces a voltage (v) = 500 - 200 = 300v.

The relationship between voltage, electric field intensity and distance is given by the formulae below

v=Ed

Where v = voltage = 300v, electric field =?, d = 0.150m

300 = E×0.150

E = 300/0.150

E = 2000 v/m.

Since point B is at higher potential than A, it implies that if there is an electron in this field, it will move from B to A thus making the direction of field be from B to A.