TOWES - Test of Workplace Essential Skills Using Diagrams and Schematics Questions and Answers — Questions and Answers
Question 1: An assembly diagram for a piece of equipment shows a part labeled with a balloon number pointing to it. What is the primary purpose of this balloon number?
- To indicate the torque specification for the part's fasteners.
- To cross-reference the part with a detailed list of components, such as a Bill of Materials. (Correct answer)
- To show the order in which the part should be painted.
- To specify the electrical voltage the part can handle.
Correct answer: To cross-reference the part with a detailed list of components, such as a Bill of Materials.
Balloon numbers on assembly drawings are used to identify individual components. Each part is assigned a unique number, which corresponds to an entry in the parts list or Bill of Materials (BOM), providing details like part name, part number, and quantity.
Question 2: While reviewing a fluid power schematic, you see a symbol composed of a circle with a 'P' inside and an arrow indicating direction of flow away from it. Which of the following does this symbol most likely represent?
- A pressure gauge
- A pilot line
- A pump (Correct answer)
- A plugged port
Correct answer: A pump
In hydraulic and pneumatic schematics, a circle is the basic symbol for a pump or motor. An arrow indicates it is a pump, and if the arrow points away from the circle, it signifies a hydraulic pump, which is the prime mover that creates flow. The 'P' often designates 'Pump'.
Question 3: A technician is troubleshooting a faulty motor using an electrical schematic. The schematic shows a zigzag line symbol labeled 'R5' connected in series with the motor. What does this symbol represent?
- A fuse
- A switch
- A capacitor
- A resistor (Correct answer)
Correct answer: A resistor
The zigzag line is the standard symbol for a resistor in electrical and electronic schematics. The 'R' designation further identifies it as a resistor, and the '5' indicates it is the fifth resistor in the circuit's design.
Question 4: You are following a piping and instrumentation diagram (P&ID) for a chemical processing plant. Which of the following is the BEST first step to understand the meaning of the various symbols on the diagram?
- Assume the symbols follow international standards and proceed with the task.
- Ask a senior operator what each symbol means.
- Locate and consult the legend or symbol key sheet for the diagram. (Correct answer)
- Search for the symbols online to find their most common meanings.
Correct answer: Locate and consult the legend or symbol key sheet for the diagram.
While many symbols are standardized, P&IDs can have specific symbols or variations unique to a company or project. The legend or symbol key is the definitive source provided with the diagram set to ensure accurate interpretation.
Question 5: An exploded-view diagram of a gearbox is provided in a service manual. What is the main advantage of this type of diagram for a mechanic?
- It shows the exact final dimensions of the assembled unit.
- It clarifies the correct order and orientation of parts for assembly or disassembly. (Correct answer)
- It provides a wiring schematic for any electrical components.
- It lists the required lubrication types and quantities.
Correct answer: It clarifies the correct order and orientation of parts for assembly or disassembly.
Exploded-view diagrams show components separated from each other but in their proper orientation and relative position. This is extremely useful for understanding how parts fit together and in what sequence they should be assembled or disassembled.
Question 6: On an electrical one-line diagram, a line representing a power cable is interrupted by a square symbol containing the letters 'CB'. What does this symbol indicate?
- A connection box
- A circuit breaker (Correct answer)
- A control board
- A capacitor bank
Correct answer: A circuit breaker
In electrical one-line diagrams and schematics, 'CB' is a common abbreviation for Circuit Breaker, a device designed to protect an electrical circuit from damage caused by overcurrent or short circuit.
TOWES - Test of Workplace Essential Skills Using Diagrams and Schematics Questions and Answers
An assembly diagram for a piece of equipment shows a part labeled with a balloon number pointing to it.
What is the primary purpose of this balloon number?