What is cyclotron? Discuss the principle,construction,theory and working of a cyclotron.What is the

Question

$\begin{array}{1 1} (a)\;E_{max}= \frac{q^2B^2}{2m}r^2_{max}\\ (b)\;E_{max}= \frac{qB}{2m}r^2_{max} \\ (c)\;E_{max}= \frac{qB}{2m}r_{max} \\ (d)\;E_{max}= \frac{q^2B^2}{r^2_{max}}\end{array}$