The imaging display where the brightness is determined by the strength of the electron beam is called:

The imaging display where the brightness is determined by the strength of the electron beam is called:

• A. Cathode ray tube
• B. Liquid crystal display
• C. Plasma display
• D. Digital micromirror device

Answer: (A)

In a cathode ray tube, brightness is controlled by the strength of the electron beam emitted by the electron gun and directed toward the phosphor-coated screen. The video signal modulates that beam current, so a stronger beam produces more light from the phosphor and a brighter pixel. This direct link between beam intensity and luminance is what defines a CRT display. Other technologies work differently: liquid crystal displays rely on backlighting and the orientation of liquid crystals to regulate light, not on an electron beam; plasma displays produce light from ionized gas discharges; and digital micromirror devices use tiny mirrors to steer light from a source, with brightness governed by the illumination and mirror state rather than electron-beam strength.

In a cathode ray tube, brightness is controlled by the strength of the electron beam emitted by the electron gun and directed toward the phosphor-coated screen. The video signal modulates that beam current, so a stronger beam produces more light from the phosphor and a brighter pixel. This direct link between beam intensity and luminance is what defines a CRT display. Other technologies work differently: liquid crystal displays rely on backlighting and the orientation of liquid crystals to regulate light, not on an electron beam; plasma displays produce light from ionized gas discharges; and digital micromirror devices use tiny mirrors to steer light from a source, with brightness governed by the illumination and mirror state rather than electron-beam strength.