In the cathode ray tube shown below, electrons are accelerated through a uniform electric field between the cathode and anode by a potential difference of 150 V. They travel through plates P and where they experience a uniform electric field of 6.00 × 106 N/C vertically downwards (denoted by the red arrows) and a uniform horizontal magnetic field of 0.826 T (denoted by the blue arrows). If the electron beam travels in a perfectly straight line, hitting the screen directly in the center, calculate , the ratio of the charge on an electron to its mass