CBSE Class 12 · 2006 · Magnetic Effects of CurrentShort Answer

\textbf{Principle:} crossed electric and magnetic fields. The magnetic field bends the charge into semicircles inside the dees, and each time it crosses the gap the alternating electric field (tuned to the cyclotron frequency $f=\frac{qB}{2\pi m}$) gives it another push, so it gains energy on every half-revolution. \textbf{Uses:} (i) to accelerate charged particles to high energies for bombarding nuclei in nuclear reactions; (ii) to produce radioisotopes used in medical diagnosis and therapy.