OIT Blueprint Reading and Technical Drawing 3

Question 1

What does the symbol '⌀' (circle with a diagonal line through it) represent in technical drawings?

Accepted Answer

The diameter of a circular feature

Answer

A null or empty value in a table

Answer

A center mark for a drilled hole

Answer

A weld all around symbol

Question 2

What is the purpose of a revision block (revision history) on a technical blueprint?

Accepted Answer

To record changes made to the drawing after original release, including date and reason

Answer

To list all the tools needed for fabrication

Answer

To show the final inspection approval signature

Answer

To indicate which standard the drawing was created under

Question 3

What do phantom lines (long dash, two short dashes pattern) represent in technical drawings?

Accepted Answer

Alternate positions of moving parts, adjacent parts, or repetitive features

Answer

Features that were removed during the design process

Answer

Internal hidden edges of the object

Answer

The path of a machining operation

Question 4

In process engineering blueprints, what does the abbreviation 'P&ID' stand for?

Accepted Answer

Piping and Instrumentation Diagram

Answer

Pipe and Insulation Diagram

Answer

Process and Installation Drawing

Answer

Pressure and Isolation Device

Question 5

What is the purpose of a break line (short wavy or zigzag line) in a technical drawing?

Accepted Answer

To show that a long object has been shortened in the drawing while maintaining its true length dimension

Answer

To indicate a weld joint location

Answer

To mark the boundary of a section view

Answer

To indicate a fractured or damaged part

Question 6

What is an auxiliary view used for in technical drawing?

Accepted Answer

To show the true shape and size of a surface that is not parallel to the standard projection planes

Answer

To provide an isometric perspective of the entire assembly

Answer

To indicate the sequence of assembly operations

Answer

To display hidden features inside the object

Question 7

When the notation 'NTS' appears on a technical drawing, what does it mean?

Accepted Answer

Not To Scale — dimensions are correct but the drawing proportions may not be accurate

Answer

No Tolerance Specified — use standard tolerance tables

Answer

National Trade Standard applies to this drawing

Answer

Non-Technical Specification — refer to text document