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  2. Cathode ray - Wikipedia

    en.wikipedia.org/wiki/Cathode_ray

    Cathode rays or electron beams (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to electrons emitted from the cathode (the electrode connected to the negative terminal of the voltage ...

  3. Ray (optics) - Wikipedia

    en.wikipedia.org/wiki/Ray_(optics)

    The entrance pupil is an image of the aperture stop formed by the optics in the front of it, and the location and size of the pupil are determined by chief rays and marginal rays, respectively. A meridional ray or tangential ray is a ray that is confined to the plane containing the system's optical axis and the object point from which the ray ...

  4. Photoelectric effect - Wikipedia

    en.wikipedia.org/wiki/Photoelectric_effect

    The phenomenological three-step model [16] for ultraviolet and soft X-ray excitation decomposes the effect into these steps: [17] [18] [19] Inner photoelectric effect in the bulk of the material that is a direct optical transition between an occupied and an unoccupied electronic state.

  5. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    The origin of the ray differentiates them, gamma rays tend to be natural phenomena originating from the unstable nucleus of an atom and X-rays are electrically generated (and hence man-made) unless they are as a result of bremsstrahlung X-radiation caused by the interaction of fast moving particles (such as beta particles) colliding with ...

  6. Sources of electrical energy - Wikipedia

    en.wikipedia.org/wiki/Sources_of_electrical_energy

    The sun's rays can be used to produce electrical energy. The direct user of sunlight is the solar cell or photovoltaic cell, which converts sunlight directly into electrical energy without the incorporation of a mechanical device. This technology is simpler than the fossil-fuel-driven systems of producing electrical energy.

  7. Photon - Wikipedia

    en.wikipedia.org/wiki/Photon

    The key new step was to identify an electromagnetic mode with energy = as a state with photons, each of energy . This approach gives the correct energy fluctuation formula. Feynman diagram of two electrons interacting by exchange of a virtual photon. Dirac took this one step further.

  8. 13-year-old has eureka moment with science project that ...

    www.aol.com/news/middle-schooler-science-project...

    Scientists have speculated about how Archimedes’ death ray purportedly harnessed sunlight to burn ships. Now, a teen may have evidence the device was plausible.

  9. Electromagnetic induction - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_induction

    For example, the drum generator is based upon the figure to the bottom-right. A different implementation of this idea is the Faraday's disc , shown in simplified form on the right. In the Faraday's disc example, the disc is rotated in a uniform magnetic field perpendicular to the disc, causing a current to flow in the radial arm due to the ...