Question

For a proton accelerated through potential difference of 1 volt kinetic energy gained in ev is

Answer 1

PE = qV where q =1.6 x 10^-19 C and V = 1000 V 

Assuming the proton no longer experiences the potential energy and it is all converted to kinetic energy then: 

PE* = 0, KE* = 1/(2mv^2)

Now since PE +KE = Total energy =PE* + KE*

qV + 0 = 0 + 1/2mv^2 

Or: KE = qV = 1.6 10^-15 J