A proton & an electron are placed freely in an electric field. Which of the particles will have greater acceleration and why?
The electron.
Because:
a=F/m
For a charged particle, the force acting depends only on the magnitude and nature of charge.
F= E q
So, as both the electron and the proton have have the same magnitude of charge, the amount of force exerted will be the same.
As, the electron has a lesser mass, it will have more acceleration.