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RGB color television and computer displays use cathode ray tubes that produce colors by mixing red, green, and blue light. If we look at the screen with a magnifying glass, we can see individual dots turn on and off as the colors change. Using a spectrum of visible light, determine the approximate wavelength of each of these colors. What is the frequency and energy of a photon of each of these colors?

a) Wavelength of red light
b) Frequency of red light
c) Energy of red light
d) Color mixing mechanism in cathode ray tubes

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Final answer:

RGB color television and computer displays use a mix of red, green, and blue light to produce colors. The approximate wavelengths, frequencies, and energies of each color can be determined using the spectrum of visible light. In cathode ray tubes, the color mixing mechanism relies on electron beams striking phosphor dots on the screen.

Step-by-step explanation:

In RGB color television and computer displays, red, green, and blue light are mixed to produce colors. The approximate wavelengths of these colors are as follows:

  1. Red light: Wavelength is approximately 620-750 nm.
  2. Green light: Wavelength is approximately 495-570 nm.
  3. Blue light: Wavelength is approximately 450-495 nm.

The frequency of a photon can be calculated using the equation: frequency = speed of light / wavelength. The speed of light is approximately 3 x 10^8 meters per second. Therefore, the frequencies of the colors are:

  1. Red light: Frequency is approximately 4 x 10^14 - 5 x 10^14 Hz.
  2. Green light: Frequency is approximately 5 x 10^14 - 6 x 10^14 Hz.
  3. Blue light: Frequency is approximately 6 x 10^14 - 7 x 10^14 Hz.

The energy of a photon can be calculated using the equation: energy = Planck's constant x frequency. Planck's constant is approximately 6.63 x 10^-34 Joule-seconds. Therefore, the energies of the colors are:

  1. Red light: Energy is approximately 2.64 x 10^-19 - 3.26 x 10^-19 Joules.
  2. Green light: Energy is approximately 3.31 x 10^-19 - 3.99 x 10^-19 Joules.
  3. Blue light: Energy is approximately 3.59 x 10^-19 - 4.14 x 10^-19 Joules.

In cathode ray tubes, the color mixing mechanism involves the use of three electron beams, each corresponding to red, green, and blue colors. These beams strike phosphor dots on the screen, causing them to emit light of the respective color. By varying the intensity of each beam, different colors can be displayed on the screen.

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