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I had a question about the following question:
In a CRT with an electromagnetic deflector, how does the energy supplied to the electron by the anode compare with the energy of the photon that is emitted after the electron strikes the screen?
*Cathode ray tubes (CRT) shown below
A. The energies are equal
B. The energy from the anode is greater than the photon's energy, because multiple photons are ejected for each electron striking the screen.
C. The photon's energy is greater than the energy from the anode.
D. The energy from the anode is greater than the photon's energy, because some energy is dissipated as heat from the screen.
I thought the answer was C because the electric field does work on the electron and this increases its energy. Therefore the energy of the electron striking the screen must be greater then the energy when it was released from the anode. However the answer stated is D. Can anyone explain this to me and why we don't account for the extra energy added by the Electric Field disregarding the magnetic field portion since it does no work. Thank you!
In a CRT with an electromagnetic deflector, how does the energy supplied to the electron by the anode compare with the energy of the photon that is emitted after the electron strikes the screen?
*Cathode ray tubes (CRT) shown below
A. The energies are equal
B. The energy from the anode is greater than the photon's energy, because multiple photons are ejected for each electron striking the screen.
C. The photon's energy is greater than the energy from the anode.
D. The energy from the anode is greater than the photon's energy, because some energy is dissipated as heat from the screen.
I thought the answer was C because the electric field does work on the electron and this increases its energy. Therefore the energy of the electron striking the screen must be greater then the energy when it was released from the anode. However the answer stated is D. Can anyone explain this to me and why we don't account for the extra energy added by the Electric Field disregarding the magnetic field portion since it does no work. Thank you!