Beam-penetration and shadow-mask are the two basic techniques for producing…
2014
Beam-penetration and shadow-mask are the two basic techniques for producing color displays with a CRT. Which of the following is not true ?
I. The beam-penetration is used with random scan monitors.
II. Shadow-mask is used in rasterscan systems.
III. Beam-penetration method is better than shadow-mask method.
IV. Shadow-mask method is better than beam-penetration method.
- A.
I and II
- B.
II and III
- C.
III only
- D.
IV only
Attempted by 85 students.
Show answer & explanation
Correct answer: C
Answer: Only statement III is not true.
I. Beam-penetration is used with random-scan monitors — True. Beam-penetration (single gun with variable beam penetration into layered phosphors) can be used in vector/random-scan displays.
II. Shadow-mask is used in raster-scan systems — True. Shadow-mask (or aperture grille) designs with three guns and a mask/aperture align phosphor triads and are standard for raster-scan color CRTs.
III. Beam-penetration method is better than shadow-mask method — False. Beam-penetration is simpler and less costly but provides poorer color accuracy, limited distinct colors, and lower overall color fidelity compared with shadow-mask systems.
IV. Shadow-mask method is better than beam-penetration method — True. Shadow-mask gives superior color reproduction and resolution, at the cost of greater complexity and manufacturing precision.
Therefore, the only incorrect statement among the four is that beam-penetration is better than shadow-mask.