ARC Welding Safety

Explanation
The correct answer is "holder" because the sentence states that stub ends should not be left in an electrode, indicating that the electrode is held or stored in something. The other options, such as storage, machine, and box, do not necessarily imply that the electrode is being held or stored in them.

Explanation
The correct answer is "filter." Safety goggles and a hand shield or helmet equipped with a suitable filter glass are necessary to protect against intense ultraviolet and infrared rays. The filter glass helps to block out these harmful rays and ensure the safety of the person wearing the goggles or shield.

Explanation
Soapstone or chalk is commonly used to mark all hot metal after welding operations are completed. This is because soapstone and chalk have high heat resistance and can withstand the high temperatures generated during welding. They can easily mark on the hot metal surface and the marks are visible even in high heat conditions. Additionally, soapstone and chalk can be easily removed or cleaned off after the welding process is completed.

Explanation
The correct answer is "flammable" because when welding, there is a risk of sparks and heat that can cause a fire if they come into contact with materials that easily catch fire or burn. Flammable materials such as cotton, oil, and gasoline can ignite and cause a dangerous situation. Therefore, it is important to remove all flammable materials from the vicinity of welding to prevent any accidents or fires from occurring.

Explanation
Flameproof aprons or jackets made of leather, fire resistant material, or other suitable material should be worn for protection against spatter of molten metal, radiated heat, and sparks. Wearing these protective garments can help prevent burns and injuries caused by exposure to high temperatures and flying debris.

Explanation
When using chippers and grinders, it is necessary to add face shields in addition to safety glasses. This implies that safety glasses alone are not sufficient for protection in these specific situations, and the addition of face shields is required to ensure maximum safety for welders.

Explanation
The correct answer is "polarity". Operating the polarity switch while the machine is operating under welding current load can cause arcing at the switch, which can damage the contact surfaces. Additionally, the flash produced by the arcing can potentially burn the person operating the switch. Therefore, it is important to avoid operating the polarity switch while the machine is in use.

Explanation
Welding may produce fumes and gases that are hazardous to health. This means that they can be harmful or dangerous if inhaled. Therefore, it is important to avoid breathing in these fumes and gases. Using adequate ventilation can help in preventing the inhalation of these hazardous substances.

Explanation
Before starting the welding operation, it is necessary to securely attach the work clamp to the workpiece. The work clamp is used to hold the workpiece in place and provide a stable connection for the welding process. Without a secure attachment, the workpiece may move or become unstable during welding, leading to poor weld quality or potential safety hazards. Therefore, it is crucial to ensure that the work clamp is securely attached to the workpiece before starting the welding operation.

Explanation
When welding is done near other personnel or students, screens should be used to protect their eyes from the arc or reflected glare. This is because welding produces intense light and heat, which can cause eye damage if proper precautions are not taken. Screens act as a barrier, blocking the harmful rays and preventing them from reaching the eyes of nearby individuals. This ensures the safety and well-being of personnel or students who may be present in the welding area.