While researching a topic, a student has taken the following notes:Digital Light Synthesis (DLS) is a form of additive manufacturing...
GMAT Expression of Ideas : (Expression) Questions
While researching a topic, a student has taken the following notes:
Digital Light Synthesis (DLS) is a form of additive manufacturing that utilizes light to rapidly cure liquid resin into high-quality, 3D objects.
- Ultraviolet (UV) light images are projected up into a pool of liquid resin, where the object's first layer takes shape.
- The partially cured resin object is raised, leaving a thin space (a 'dead zone') beneath it for oxygen and liquid resin to flow through.
- The UV light passes through the dead zone—maintaining the flow of resin—and partially cures additional layers of the object.
- When the resin object is complete, it is baked in an oven to complete the curing.
The student wants to describe how DLS cures 3D objects. Which choice most effectively uses relevant information from the notes to accomplish this goal?
DLS is a form of additive manufacturing that creates a 'dead zone' in which UV light solidifies layer by layer before being baked in an oven, creating a high-quality, 3D object.
DLS cures 3D objects by passing through a 'dead zone,' adding layers to the object, then curing the object in an oven.
In DLS, UV light images are projected into a liquid resin pool to cure a 3D object layer by layer; once solidified, the object is baked in an oven.
In DLS, UV light is projected into layers of liquid resin until the resin solidifies and passes through a 'dead zone,' wherein the curing is completed.
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Digital Light Synthesis (DLS) is a form of additive manufacturing that utilizes light to rapidly cure liquid resin into high-quality, 3D objects." |
|
| "Step 1: Ultraviolet (UV) light images are projected up into a pool of liquid resin, where the object's first layer takes shape." |
|
| "Step 2: The partially cured resin object is raised, leaving a thin space (a 'dead zone') beneath it for oxygen and liquid resin to flow through." |
|
| "Step 3: The UV light passes through the dead zone—maintaining the flow of resin—and partially cures additional layers of the object." |
|
| "Step 4: When the resin object is complete, it is baked in an oven to complete the curing." |
|
Part B: Provide Passage Architecture & Core Elements
- Main Point: DLS creates 3D objects through a four-step process involving UV light projection into resin pools followed by oven curing.
- Argument Flow: The passage first defines DLS, then systematically walks through its four-step manufacturing process, showing how UV light and resin interaction creates layered objects that are finally completed through oven curing.
Step 2: Interpret the Question Precisely
What's being asked? Which choice most effectively describes how DLS cures 3D objects using the student's notes.
What type of answer do we need? A synthesis that accurately captures the curing process from the notes.
Any limiting keywords? "most effectively" means we need the choice that best accomplishes the goal of describing the curing process, and "uses relevant information from the notes" means it should draw from the actual content provided.
- For rhetorical synthesis questions, we need to focus on the student's specific goal: describing HOW DLS cures 3D objects. This means we're looking for a choice that captures the essential mechanism and process flow.
Step 3: Prethink the Answer
- The correct answer should capture the core curing mechanism—UV light being projected into liquid resin to cure objects layer by layer
- It should also mention the final oven step since that completes the curing process
- The answer doesn't necessarily need every detail (like the dead zone mechanics) as long as it effectively describes HOW the curing happens
- The right answer should explain that UV light projects into resin pools to cure objects layer by layer, followed by oven baking to complete the process
DLS is a form of additive manufacturing that creates a 'dead zone' in which UV light solidifies layer by layer before being baked in an oven, creating a high-quality, 3D object.
✗ Incorrect
- Suggests UV light solidifies within the dead zone itself
- Misrepresents the dead zone's function—it's for resin/oxygen flow, not where curing happens
- What trap this represents: Students might confuse the dead zone as the curing location rather than understanding it as a flow mechanism
DLS cures 3D objects by passing through a 'dead zone,' adding layers to the object, then curing the object in an oven.
✗ Incorrect
- Says "DLS cures objects by passing through a dead zone"—makes no sense
- Missing the crucial UV light mechanism entirely
- Doesn't explain HOW the curing actually works
In DLS, UV light images are projected into a liquid resin pool to cure a 3D object layer by layer; once solidified, the object is baked in an oven.
✓ Correct
- Accurately describes UV light projection into resin pool for layer-by-layer curing
- Includes the final oven step that completes the curing
- Focuses on the essential HOW without getting lost in dead zone mechanics
- Matches our prethinking perfectly
In DLS, UV light is projected into layers of liquid resin until the resin solidifies and passes through a 'dead zone,' wherein the curing is completed.
✗ Incorrect
- Suggests resin "passes through" the dead zone
- Claims curing is "completed" in the dead zone, contradicting the notes about oven finishing
- What trap this represents: Students might misunderstand the sequence and think the dead zone is where final curing occurs