A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 kV its kinetic energy will be:
The charge on a proton is equal to e, the electronic charge. The potential difference is V = 1 kV. Hence the kinetic energy of the proton is E = 1 keV.
We know that :
Kinetic energy = Relative charge × accelerating potential
KE = 1e × 1kV
KE = 1keV