Question

Point A is at a potential of +250 V and point B is at a potential of -150 V. An alpha particle starts at A and accelerates towards B. When the article arrives at B, what kinetic energy (in electron volts) does it have?

Answer 1

Net potential difference$=250-(-150)V=400V$

Charge on alpha particle$=2e$

Kinetic energy of alpha particle$=qV=2eV=800eV$