Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 1612:00 PM EDT
-11:59 PM EDT
You’re first to know: Save $200 on GMAT prep starting tomorrow, 4/13. Get 6 official practice tests and study with real questions. Be ready to save!
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
07 Dec 2012, 12:12
Kudos
Bookmarks
Despite their acronymic similarity, LEDs and LCDs represent distinct display technologies. In LEDs, or light-emitting diodes, two different semiconductor materials are layered together: n-type, in which mobile electrons carry negative charge, and p-type, in which “holes” in an otherwise bound sea of electrons carry positive charge. When electric current flows through the p-n junction between layers, an n-type electron falling into a p-type hole releases a photon, a specifically colored particle of light.
The dominant technology currently used in most consumer product displays is the active matrix liquid crystal diode display (LCD). LCDs apply thin-film transistors (TFTs) of amorphous silicon sandwiched between two glass plates. The TFTs supply voltage to liquid-crystal-filled cells, or pixels, between the sheets of glass. Liquid crystals can twist the polarization, or wave orientation, of light. Just as a guitar string can vibrate sideways or up and down, so a light wave can be polarized horizontally or vertically. Polarizing filters act as selective gates, transmitting light polarized one way but not the other. Within a pixel, liquid crystals in their relaxed, coiled state rotate the polarization of ambient light enough to make surrounding filters transparent. Alternatively, applied electrical signals uncoil the crystals, causing the filters to block light and the pixel to become opaque. 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.
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. The dense array of crystals displays images from computer sources extremely well, with full color detail, no flicker, and no screen burn-in. Moreover, the number of pixels per square inch on an LCD is typically higher than that for other display technologies; LCD monitors are excellent at displaying large amounts of data with exceptional clarity and precision.
Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
A They are opaque to ambient light.
B They are in a relaxed state, in comparison to their high-energy coiled state.
C They are found in one of two wave orientations, horizontal or vertical.
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters.
E They cause the pixel to become transparent.
The dominant technology currently used in most consumer product displays is the active matrix liquid crystal diode display (LCD). LCDs apply thin-film transistors (TFTs) of amorphous silicon sandwiched between two glass plates. The TFTs supply voltage to liquid-crystal-filled cells, or pixels, between the sheets of glass. Liquid crystals can twist the polarization, or wave orientation, of light. Just as a guitar string can vibrate sideways or up and down, so a light wave can be polarized horizontally or vertically. Polarizing filters act as selective gates, transmitting light polarized one way but not the other. Within a pixel, liquid crystals in their relaxed, coiled state rotate the polarization of ambient light enough to make surrounding filters transparent. Alternatively, applied electrical signals uncoil the crystals, causing the filters to block light and the pixel to become opaque. 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.
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. The dense array of crystals displays images from computer sources extremely well, with full color detail, no flicker, and no screen burn-in. Moreover, the number of pixels per square inch on an LCD is typically higher than that for other display technologies; LCD monitors are excellent at displaying large amounts of data with exceptional clarity and precision.
Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
A They are opaque to ambient light.
B They are in a relaxed state, in comparison to their high-energy coiled state.
C They are found in one of two wave orientations, horizontal or vertical.
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters.
E They cause the pixel to become transparent.
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Reading Comprehension (RC) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
plumber250
Joined: 07 Nov 2012
Last visit: 21 Dec 2015
Posts: 213
Own Kudos:
Given Kudos: 4
Schools: LBS '14 (A$)
GMAT 1: 770 Q48 V48
08 Dec 2012, 12:30
Kudos
Bookmarks
Hi,
Let me see if I can help, here's my thought process...
Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
OK. So need to scan through passage to find section talking about uncoiled liquid crystals and read that bit thoroughly...
Polarizing filters act as selective gates, transmitting light polarized one way but not the other. Within a pixel, liquid crystals in their relaxed, coiled state rotate the polarization of ambient light enough to make surrounding filters transparent. Alternatively, applied electrical signals uncoil the crystals, causing the filters to block light and the pixel to become opaque.
Found it. Now for the answer choices...
A They are opaque to ambient light. No, this doesn't work.. We're told as a FACT that it blocks light, we have no reason to assume ambient light is affected any differently to other light, so nothing inferred here.
B They are in a relaxed state, in comparison to their high-energy coiled state. No this is actually incorrect. We're told that crystals are relaxed in their coiled state
C They are found in one of two wave orientations, horizontal or vertical.No, these 2 orientations are mentioned, but not in relation to the liquid crystals
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters. Looks good. Correct. We are told that coiled crystals rotate to allow light photons through. We know uncoilded crystals do not allow light photons through, it is inferred that this is the reason why
E They cause the pixel to become transparent. No this doesn't work. We see something about opaque, nothing about any transparency
Hope it helps. James
Let me see if I can help, here's my thought process...
Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
OK. So need to scan through passage to find section talking about uncoiled liquid crystals and read that bit thoroughly...
Polarizing filters act as selective gates, transmitting light polarized one way but not the other. Within a pixel, liquid crystals in their relaxed, coiled state rotate the polarization of ambient light enough to make surrounding filters transparent. Alternatively, applied electrical signals uncoil the crystals, causing the filters to block light and the pixel to become opaque.
Found it. Now for the answer choices...
A They are opaque to ambient light. No, this doesn't work.. We're told as a FACT that it blocks light, we have no reason to assume ambient light is affected any differently to other light, so nothing inferred here.
B They are in a relaxed state, in comparison to their high-energy coiled state. No this is actually incorrect. We're told that crystals are relaxed in their coiled state
C They are found in one of two wave orientations, horizontal or vertical.No, these 2 orientations are mentioned, but not in relation to the liquid crystals
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters. Looks good. Correct. We are told that coiled crystals rotate to allow light photons through. We know uncoilded crystals do not allow light photons through, it is inferred that this is the reason why
E They cause the pixel to become transparent. No this doesn't work. We see something about opaque, nothing about any transparency
Hope it helps. James
09 Dec 2012, 07:31
Kudos
Bookmarks
Which of the following can be inferred about uncoiled liquid crystals in an LCD pixel?
A They are opaque to ambient light.
a very nice distractor, It is surrounding filter which becomes opaque or transparent by the action of crystal not crystal itself
B They are in a relaxed state, in comparison to their high-energy coiled state.
This is opposite answer.
C They are found in one of two wave orientations, horizontal or vertical.
They make light photons polarized not get polarized themselves
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters.
A difficult but correct inference. Passage says the coiled ones in relaxed state allow light to pass through filters amd they act as transparent. And the uncoiled ones make filters opaque by doing something to polarization of light. what they do is mentioned in D .
E They cause the pixel to become transparent.
not transparent but opaque
A They are opaque to ambient light.
a very nice distractor, It is surrounding filter which becomes opaque or transparent by the action of crystal not crystal itself
B They are in a relaxed state, in comparison to their high-energy coiled state.
This is opposite answer.
C They are found in one of two wave orientations, horizontal or vertical.
They make light photons polarized not get polarized themselves
D They fail to rotate the polarization of surrounding photons enough to allow them to pass through nearby filters.
A difficult but correct inference. Passage says the coiled ones in relaxed state allow light to pass through filters amd they act as transparent. And the uncoiled ones make filters opaque by doing something to polarization of light. what they do is mentioned in D .
E They cause the pixel to become transparent.
not transparent but opaque
