Before the development of LCD and plasma televisions, cathode rays were commonly used in television sets. An electric field would cause electrons to accelerate and then magnetic coils would be used to direct the beam of electrons to various positions on a screen covered in phosphorus. When the electrons struck the phosphorus, it would create tiny dots of red, blue or green light. Moving the electron beam across the screen at high speeds would then generate an image. a. If a beam of electrons in a television set is deflected into a circular path with a radius of 0. 106 mm while travelling through a perpendicular magnetic field with a strength of 0.0700 T, what speed were the electrons travelling at? b. Determine the potential difference required to get an electron to reach this speed. B I E U S X2 X2 D C CClear my choice A charged particle of unknown identity is sent through a cathode ray tube. It then enters a perpendicular magnetic field of 0.30 T with a speed of 4.0 x 10 m/s and follows a circular path with a radius of 9.0 cm. The charge-to-mass ratio of this unknown particle is Select one: O a. 6.8 x 10-8 C/kg O b. 6.8 x 10-7 C/kg O c. 1.5 x 105 C/kg O d. 1.5 x 108 C/kg Rutherford's nuclear model must be invalid because Select one: O a. a nucleus cannot exist in close proximity to electrons O b. accelerating charges should produce EMR O c. Thomson had proven that atoms are solid O d. electrons are waves A line-absorption spectra may be produced by Select one: O a. placing a large potential difference across a gas filled CRT O b. shining white light through a gas at room temperature O c. placing a chemical into a Bunsen burner flame O d. heating a gas to a very high temperature