Chapter 4: Display Devices

1. C. LCDs do not have electron guns that are aimed by magnets as CRTs do. This difference makes LCDs more compatible with nearby speaker magnets. Additionally, the cathode ray tube for which CRT monitors are named is a rather bulky component, requiring more desk space to accommodate the CRT’s cabinet. Projectors are not common personal display devices; they are used more in group environments. HDMI is a standard for connecting display devices, not a type of display device.

2. B. The associate is trying to think of the term dot pitch. Essentially, dot pitch is the height of a dot-phosphor trio added to the distance between the next dot trio in the same direction. It works out to be the distance from any point on one dot to the same point on the next dot of the same color. The smaller this number, the better the display quality. The number of dots per inch is a similar concept but inversely proportional and not measured in fractions of a millimeter. Resolution is a software concept; dot phosphors are hardware related. The refresh rate has nothing to do with how close the chemical dots are to one another.

3. D. The maximum allowable refresh rate does tend to be affected by the resolution you choose in the operating system. The refresh rate is most often expressed in cycles per second (Hz), not millions of cycles per second (MHz). You must usually select the refresh rate you want from the display settings dialog boxes, not through the monitor’s built-in menu system, although the monitor’s system can often tell you which refresh rate you’re using. Finally, both the monitor and adapter must agree on the refresh rate you select. If either device does not support a particular refresh rate, such a rate cannot be used.

4. C. At the same resolution, CRTs are more likely to display a clearer image than LCDs. LCDs are normally limited to a fixed, native resolution but require less power than CRT monitors. Although LCD screens are not regularly and systematically refreshed the way CRTs are, the LCD refresh rate dictates how often any one pixel is allowed to change.

5. A. The amount of memory installed on a graphics adapter is directly related to how many pixels can be displayed at one time and how many colors the pixels can be set to. Monitors don’t have memory installed in them. LCDs, not CRTs, have a single, fixed resolution called the native resolution. By default, you might be limited to a particular refresh rate because the resolution is too high, but the refresh rate is automatically adjusted down, if necessary, when you select a resolution.

6. B. SXGA has a resolution of 1280×1024. Consult Table 4-1 for the resolutions that characterize other technologies.

7. D. Although the Q stands for quad, the pixel count for each axis is only doubled, resulting in four times as many total pixels.

8. A. Contrast ratio is a selling point for LCDs. Higher contrast ratios mean darker blacks and brighter whites. The measure of luminance between adjacent pixels is known as contrast, not contrast ratio.

9. D. Both OLED and plasma displays use electrodes to excite the material in a sealed chamber to produce light. Each in its own way uses that light to create red, green, or blue light within individual subpixels. Plasma is more akin to CRT in that they both use chemical phosphors to create the red, green, and blue hues. In contrast to the way CRTs and PDPs produce color, OLEDs natively produce these colors of light without the use of filters or phosphors.

10. C, E. Older LCD panels might have employed a passive-matrix addressing for their pixels, resulting in a poorer viewing angle than that created by active-matrix LCD panels. Additionally, privacy filters intentionally limit the angle of screen visibility by changing the light’s polarization when viewed from the side. Antiglare filters might unintentionally do the same thing.

11. B. Although it’s true that you must start with the Display Settings dialog box, which ironically shows a single tab labeled Monitor, and that you subsequently click the Advanced Settings button, it’s on the Monitor properties tab thereafter that you select the refresh rate. The Adapter tab in those same properties pages has no selection for refresh rate.

12. A. Unplugging the power to the projector before the projector’s fan has had the opportunity to cool the unit and stop running on its own can lead to expensive repairs on the projector or to the cost of replacing the projector outright.

13. D. Safe Mode in XP disables as many nonessential drivers and services as possible. One of the nonessential drivers it disables is the driver for the graphics adapter. Windows uses its standard VGA driver to control the graphics adapter while you are in Safe Mode. Another reason for defaulting back to standard VGA is that you might have a corrupt or incorrect driver for your adapter.

14. C. If your monitor allows you to change the resolution, it might not actually allow you to change the resolution. As confusing as that sounds, your monitor might maintain its optimal hardware resolution, such as an LCD’s native resolution, and force you to scroll to see any pixels created by the chosen software resolution that it cannot fit on the hardware screen at that particular moment.

15. A. An LCD’s native resolution is the single, fixed resolution that provides optimal clarity.

16. D. The multimonitor feature allows two monitors to display exactly the same thing (clone) or to extend your Desktop onto the second monitor. There is no need to use one adapter to achieve this result. In fact, the two adapters don’t even have to use the same expansion-bus architecture. The two cards must, however, use the same graphics-adapter driver.

17. A. Active matrix technology is superior to passive matrix. Dual scan is merely an enhanced form of passive matrix but is not on par with active matrix. Dual matrix isn’t an LCD type.

18. B. Dividing 16 by 10 produces a value of 1.6. Dividing the first number of a 16:10 resolution by the second number always results in 1.6. Resolutions with a 4:3 aspect ratio produce the value 1.333, while 5:4 resolutions such as 1280×1024 produce the value 1.25.

19. C. The built-in degaussing tool of the latest CRT monitors is designed to work with the monitor in which it is found. External degaussing tools, while effective, can be a little hard on the delicate inner workings of the CRT. Software alone cannot degauss a CRT monitor.

20. B. A lumen is a unit of measure for the total amount of visible light that the projector gives off, based solely on what the human eye can perceive.