Cyclotron Questions

A proton carrying $1\text{MeV}$ kinetic energy is moving in a circular path of radius $R$ in uniform magnetic field. What should be the energy of an $\alpha$ -particle to describe a circle of same radius in the same field?

An alternating electric field, of frequency $\nu$, is applied across the dees (radius $=R$) of a cyclotron that is being used to accelerate protons (mass $=m$). The operating magnetic field ($B$) used in the cyclotron and the kinetic energy ($K$) of the proton beam are: