8 Extremely hard Physics Questions that will outsmart you! (Solved)
1) An electron with velocity v =2 × 106 ms-1 enters a square region ABCD (of area a=1cm2 along one of its side AB. Inside the region there is a magnetic field B perpendicular to the area of the square. Find the minimum value of magnetic field for which the electron will come out of the square with a velocity parallel to its initial velocity(parallel doesn't necessarily mean in the same direction) The magnetic force acting on the electron is given by F = q(v x B), where q is the charge of the electron and B is the magnetic field. Since the electron is entering the square region with velocity v parallel to side AB, the magnetic force will be perpendicular to the velocity of the electron, causing it to move in a circular path. In order for the electron to exit the square with a velocity parallel to its initial velocity, the net force on the electron must be zero. This means that the magnetic force must be equal in magnitude but opposite in direction to the centripetal force, which is
