Welding textbook CH 7

Which AWS specification covers electrodes used for welding low-alloy steels?

• A.5.9

• A.5.18

• A.5.28

• A.5.30

For GTAW or GMAW, the electrode is held in a(n) ____.

• electrode holder

• electrode clamp

• gas welding torch

• GTAW torch or GMAW gun

When a constant voltage machine is used, a ____.

• small percentage change in voltage leads to a smaller percentage change in current

• small percentage change in current leads to a smaller percentage change in voltage

• large percentage change in voltage leads to a larger percentage change in current

• small percentage change in voltage leads to a larger percentage change in current

When a constant current welding machine is used, a ____.

• small percentage change in voltage leads to a larger percentage change in current

• large percentage change in voltage leads to a smaller percentage change in current

• large percentage change in voltage leads to a larger percentage change in current

• large percentage change in current leads to a smaller percentage change in voltage

Which shielding gas provides the best cleaning action, cross-draft protection, and the lowest overall cost?

• Helium

• Carbon dioxide

• Nitrogen

• Argon

A flowmeter measures and controls the ____ of the gas flow.

• pressure and volume

• pressure

• volume

• density

The maximum current generally used on a light-duty shielding gas-cooled GTAW torch is ____ amperes.

• 45

• 75

• 150

• 200

Which of the following determines the nozzle diameter selected for GTAW or GMAW?

• The volume of shielding gas to be used.

• The type of shielding gas used.

• The thickness and angle of the joint.

• The volume of gas and the size of the joint opening.

Thoriated tungsten electrodes are used because they ______ than other types of electrodes.

• can carry a higher amperage

• have a higher resistance to contamination

• strike an arc more easily

• all of the above

The color band on a 2% thoriated electrode is ______.

• red
• green

• black

• none of the above