CPI Blueprint & Schematic Interpretation 2 — Questions and Answers
Question 1: On an electrical schematic, what does a dashed line between two components typically represent?
- A ground connection
- A mechanical linkage or association (Correct answer)
- A high-voltage conductor
- A fused circuit path
Correct answer: A mechanical linkage or association
Dashed lines on schematics indicate a mechanical linkage, enclosure boundary, or non-electrical association between components.
Question 2: A blueprint dimension shown as '4'-6"' means the measurement is:
- 4.6 feet
- 4 feet 6 inches (Correct answer)
- 46 inches
- 4 meters 6 centimeters
Correct answer: 4 feet 6 inches
The foot-inch notation uses an apostrophe for feet and quotation mark for inches, so 4'-6" equals 4 feet and 6 inches.
Question 3: Which view in a set of blueprints shows the building from above looking straight down?
- Elevation view
- Section view
- Plan view (Correct answer)
- Detail view
Correct answer: Plan view
A plan view (floor plan) is a horizontal cut through the structure viewed from above, showing layout and dimensions.
Question 4: On a piping and instrumentation diagram (P&ID), what does a circle with a letter-number tag represent?
- A valve type
- An instrument or control device (Correct answer)
- A pump
- A pipe reducer
Correct answer: An instrument or control device
Tagged circles (bubbles) on a P&ID represent instruments such as transmitters, indicators, controllers, or recorders.
Question 5: When a blueprint note reads 'NTS,' it means:
- Not to scale (Correct answer)
- New tension spec
- Number of threads specified
- Non-threaded section
Correct answer: Not to scale
NTS stands for 'Not to Scale,' warning the reader that the drawing dimensions should not be measured directly from the printed image.
Question 6: A section view on a blueprint is created by:
- Viewing the object from the side at eye level
- Cutting through the object and viewing the exposed interior (Correct answer)
- Rotating the object 90 degrees on the plan
- Enlarging a small detail for clarity
Correct answer: Cutting through the object and viewing the exposed interior
A section view imagines slicing the object along a cutting-plane line and then viewing the exposed cross-section.
Question 7: On a schematic diagram, the symbol for a normally open (NO) push-button switch shows:
- Two parallel lines with no gap
- A diagonal line across the contact symbol
- An open gap between two contact lines with an actuator arrow (Correct answer)
- A circle with an X through it
Correct answer: An open gap between two contact lines with an actuator arrow
A normally open push-button has separated contact lines (open gap) and an arrow or actuator symbol indicating it closes only when pressed.
CPI Blueprint & Schematic Interpretation 2
On an electrical schematic, what does a dashed line between two components typically represent?