Question

in a region of uniform electric field as an electron travels from A to B, its velocity reduces from Va to Vb. change in potential can be given as?

Answer 1

The numerical value of change in potential energy (U) = 0.5 x m x [(Va)^2 - (Vb)^2] (where m is the mass of the electron and Va and Vb are the speeds at two different locations A and B)

The change in potential energy is numerically equal to the change in kinetic energy according to Work Energy theorem.

Initial velocity = 0.5 x m x (Va)^2
Final velocity = 0.5 x m x (Vb)^2
Change in velocity = 0.5 x m x [(Va)^2 - (Vb)^2]

Hence change in potential energy (U) = 0.5 x m x [(Va)^2 - (Vb)^2].