1. A beam of charged particles passes through a vacuum chamber and strikes the centre of the fluorescent screen at the end of the chamber. When a magnetic field B is applied in the direction shown, two spots appear on the screen, one 1 cm above the centre, and one 8 cm above the centre. Which of the following can be possible constituents of the beam? i) protons and alpha particles, traveling at the same speedii) protons traveling with speed v and alpha particles traveling with speed 4viii) electrons and protons, traveling at the same speediv) electrons and alpha particles, traveling at the same speed
更新1:
the direction of B is into the paper