C) Hypnosis Certification this is only showing your certification and not a method of hypnosis
Answer and Explanation:
(a) The attached image below shows the diagram of a CRT in the helmholtz coils and well labelled with details
(b). The electron will follow a circular path which travels along under constant magnetic field

where m = mass of electron, V = velocity of electron, q = charge of the electron and B = magnetic field strength
Mechanical waves transfer energy by inducing vibrations in the propagation medium.