P1 - LCD n LED defined.
P2 - how LCD works, colours, uses.
p3 - lcd is better then plasma. why how?
1. According to the passage, the application of an electrical signal or current to both an LED and an LCD pixel results in which of the following?
Alternatively, applied electrical signals uncoil the crystals, causing the filters to block light and the pixel to become opaque
releases a photon, a specifically colored particle of light.
C. The LED becomes bright, but the LCD pixel ceases to transmit light. - no
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2. The author most likely mentions “ plasma ” in the third paragraph in order to
The amount of power required to untwist the crystals to display images is much lower than that required for analogous processes using other technologies, such as plasma.
A. provide an example of a technology that operates differently than LCDs -
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3. The process through which an LCD monitor displays different colors is most closely analogous to
LCDs that are capable of producing color images, such as in televisions and computers, reproduce colors by blocking out particular color wavelengths from the spectrum of white light until only the desired color remains. The variation of the intensity of light permitted to pass through the matrix of liquid crystals enables LCD displays to present images full of gradations of different colors.
PT - Similarity is that something can pass while other can be blocked.
B. the use of rigid sizing boxes at an airport security checkpoint in order to allow the passage of certain sizes of luggage while excluding other sizes of luggage -
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4. Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
P2
Within a pixel, liquid crystals in their relaxed, coiled state rotate the polarization of ambient light enough to make surrounding filters transparent.
The dominant technology currently used in most consumer product displays is the active matrix liquid crystal diode display (LCD).
A. Electric currents cause them to release photons. --- that is in LCD.
B. They are in a relaxed state, in comparison to their high-energy coiled state. ---- comparision part is not correct.
C. They are found in one of two wave orientations, horizontal or vertical. --- no >>>>>>>>>so a light wave can be polarized horizontally or vertically.
D. They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters. --- others can be elliminated easily .
E. They cause the pixel to become transparent. - no >>>> make surrounding filters transparent
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5.In this passage, the author is primarily concerned with
A. delineating the commonalities between two seemingly divergent phenomena
B. contrasting the uses of electrical power for two contrary purposes
C. explicating the scientific underpinnings of two dissimilar technologies - clearly best of the lot.
D. describing the economic significance of two processes
E. analyzing the relationship between two methods of displaying information
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