Question

high frequency is best controlled in a welding shop by ____ __ all electrically conductive materials in a ____ diameter sphere.

using a work clamp/100 foot
earth grounding/50 foot
using a work clamp/50 foot
earth grounding/100 foot

Explanation:

Identify the core safety standard

Using the Earth Grounding knowledge point
High-frequency (HF) radiation from GTAW (TIG) power sources can cause severe electromagnetic interference with nearby electrical equipment, computers, and CNC machinery. To control and minimize this high-frequency interference, standard welding codes (such as AWS and power source manufacturer guidelines) specify grounding procedures.

Determine the grounding method and range

Using the Earth Grounding knowledge point
The standard practice to prevent HF feedback and radiation is earth grounding all electrically conductive materials (such as metal building structures, pipes, and workbenches) located within a 50-foot radius (or 50-foot diameter sphere centered on the spark gap/welding machine).

Match with the given options

Using the Earth Grounding knowledge point

• The first blank requires the method: "earth grounding".
• The second blank requires the distance: "50 foot".
• This matches the option: "Earth grounding/50 foot".

Answer:

• Using a work clamp/100 foot
• Earth grounding/50 foot (Correct answer)
• Using a work clamp/50 foot
• Earth grounding/100 foot