Chapter 4 - Display Devices Flashcards
Which of the following would be the best choice as a personal display technology if a user wants to save desk space and not have to deal with interference from nearby speakers? A. CRT B. HDMI C. LCD D. Projector
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.
An associate is trying to explain why a particular model of CRT monitor displays images in such high quality but is unable to recall a specific term. The associate mentions that each phosphor is on average only 0.25mm away from the nearest phosphor of the same color.
What is the associate trying to describe?
A. Resolution
B. Dot pitch
C. Refresh rate
D. The number of dots per inch
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.
Which of the following is true regarding a monitor’s refresh rate?
A. As long as the graphics adapter can refresh the image at a particular rate, the attached monitor can accommodate that refresh rate.
B. The refresh rate is normally expressed in MHz.
C. The refresh rate is normally selected by using the controls on the front panel of the monitor.
D. As you lower the resolution, the maximum refresh rate allowed tends to increase.
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.
Which statement about LCDs is most accurate?
A. The concept of refresh rate has no meaning with regard to LCDs.
B. LCDs are preferred to CRTs because they can display a larger range of resolutions.
C. LCDs tend not to be as clear as CRTs.
D. LCDs require more power than CRTs.
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.
If you are unable to display a given resolution on a monitor, which of the following might explain why?
A. The graphics adapter does not have enough memory installed.
B. The video display unit does not have enough memory installed.
C. You are using a CRT with a single fixed resolution.
D. You have the refresh rate set too high.
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.
Which video technology has a resolution of 1280n1024? A. SVGA B. SXGA C. WSXGA D. UXGA
B. SXGA has a resolution of 1280n1024. Consult Table 4.1 for the resolutions that characterize other technologies.
What does a Q in video resolution names, such as QXGA, refer to?
A. Both the horizontal and vertical components of the resolution have been quadrupled.
B. The resolution is cut to one-fourth.
C. The technology is faster.
D. Both the horizontal and vertical components of the resolution have been doubled.
D. Although the Q stands for quad, the pixel count for each axis is only doubled, resulting in four times as many total pixels.
What is contrast ratio?
A. The ratio of luminance between the darkest and lightest colors that can be displayed
B. A term that was used with CRTs but has no meaning with LCDs
C. The ratio of luminance between two adjacent pixels
D. Something that can be corrected through degaussing
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.
Which of the following display types physically creates the image displayed in a manner most similar to OLED displays? A. CRT B. LED C. LCD D. Plasma
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.
When approaching an older LCD panel from the side, you don’t realize there is actually an image displayed on it until you are almost in front of it. Which two options might explain why you could not detect the image from the side? (Choose two.)
A. Older LCDs were equipped with a motion sensor.
B. Multiple monitors are in use, and the LCD is the secondary monitor, resulting in its poor oblique visibility.
C. The user has a privacy filter in place.
D. The monitor employs active-matrix pixel addressing.
E. It is a passive-matrix LCD panel.
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.
On which properties tab do you select the refresh rate to use between the graphics adapter and monitor in Windows Vista? A. Adapter B. Monitor C. Advanced D. Display Settings
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.
After a presentation using a video projector, when in a hurry to pack everything up and head to the airport, which of the following should you avoid doing immediately?
A. Unplugging the projector’s power cable
B. Unplugging the projector’s video cable from your laptop
C. Powering down the projector
D. Turning off your laptop
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.
What might cause your display to appear in a resolution of 640n480?
A. You have your resolution set to SVGA.
B. You added memory to your graphics adapter but have not informed the BIOS of the new memory.
C. You have your resolution set to XGA.
D. You have booted XP into Safe Mode.
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.
Which of the following results can occur with improper display settings?
A. The computer spontaneously reboots.
B. The graphics adapter automatically chooses to use the highest supported resolution.
C. You might have to scroll to see parts of the Desktop.
D. The mouse cursor changes or permanently disappears.
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.
What is the single, fixed resolution of an LCD called? A. Native resolution B. Default resolution C. Refresh rate D. Burned-in resolution
A. An LCD’s native resolution is the single, fixed resolution that provides optimal clarity.
