Electrons are fired at different speeds through a magnetic field and are bent from their straight-line paths to hit the detector at the points shown. Rank the speeds of the electrons from highest to lowest.

Solution 1R Step 1: Suppose, this is the deflection for electrons as they move through a constant magnetic field. For the electrons with small momentum, the deflection will be more since the force by magnetic field can influence it more. For the electron with high momentum, the deflection of the path will be comparatively lesser. Since A,B and C in figure 1 are electrons. Their masses will be same. So, in order to have different momentum, their velocities may be different. So, for higher momentum electrons, the velocity will be higher and for lower momentum, the velocity will be smaller. Here, as per the deflection the momentum will be, P < PC< PA B Hence, the speed of the electrons A, B and C will be, C