5. What percent duty cycle do most heavy-duty industrial machines used for manual weld- ing have? a. 50 b. 100 c. 50 to 60 d. 60 to 100

The correct answer is c. 50 to 60.<br /><br />Most heavy-duty industrial machines used for manual welding typically have a duty cycle of 50 to 60 percent. The duty cycle refers to the percentage of time that a machine can operate continuously without overheating or requiring a rest period. A 50 to 60 percent duty cycle means that the machine can operate for 50 to 60 percent of the time, with the remaining time allocated for cooling down before it can be used again. This range is common for heavy-duty industrial machines as it allows for a balance between performance and heat dissipation.