A cyclotron is a device for accelerating charged particles to high speed as they follow an expanding spiral-like path. The charged particles are subjected to both an electric field and a magnetic field. One of these fields increases the speed of the charged particles, and the other field causes them to follow a curved path. Which field performs which function? The magnetic field in a cyclotron forces the particles to higher speeds, while the electric field forces the particles into curved paths. The electric and magnetic fields in a cyclotron force the particles to higher speeds, while only the magnetic field forces the particles into curved paths. The electric field in a cyclotron forces the particles to higher speeds, while the magnetic field forces the particles into curved paths