pg. 1 CWB Module 1 Actual Exam Latest 2024 – 2025/ Complete 200 Real Exam Questions with Correct Verified Answers.
What is mechanical ventilation? - Correct Answer - The use of fans or air blowers in the removal of contaminants in air.
What does the effectiveness of general ventilation depend on? (multiple answers possible)
a) Concentration and toxicity of contaminant
b) The rate at which the air is exchanged
c) The higher the air exchange rate the more effective
- location of inlet and exhaust
Correct Answer –
a) Concentration and toxicity of contaminant
b) The rate at which the air is exchanged
- location of inlet and exhaust
Which of the following is a local exhaust system:
- welding bench with fixed hood
- downdraft bench
- updraft bench
- fume extracting gun
- portable hood
Correct Answer – 1 / 4
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- welding bench with fixed hood
- downdraft bench
- fume extracting gun
- portable hood
What rate must the air velocity need to have to capture fume ideally?
- 5m/sec (1000ft/min)
- 0.5m/sec (100ft/min)
- 0.005m/sec (1ft/min) - Correct Answer - b) 0.5m/sec (100ft/min)
Why is very high air velocity bad for the welding?
a) It distracts the welder
b) It may cause fire with the sparks
c) It may result in poor weld quality - Correct Answer - c) It may result in poor weld
quality
What of the following can go wrong when placing the hood to capture fumes?
- hood is placed too close to welding zone
- hood is placed too far from welding zone - Correct Answer - b) hood is placed too far
from welding zone
What personal protection devices can welders use when exhaust will not be enough or convenient?
- no protection is needed
- a tissue placed on mouth and nose 2 / 4
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- masks and respirators - Correct Answer - c) masks and respirators
Which of the following are respirators that welders could use for personal protection?
- disposible dust/mist respirators
- half face respirators
- full face respirators
- powered air purifying respirators - Correct Answer - a) disposible dust/mist respirators
- half face respirators
- full face respirators
- powered air purifying respirators
Why are disposible dust/mist respirators less effective than others?
- they are inexpensive but cause high cost due to regular orders
- standard size and therefore not well sealed
- they provide no protection from gases and offer only limited protection from welding
- they provide no protection from gases and offer only limited protection from welding
fumes - Correct Answer - b) standard size and therefore not well sealed
fumes
Which of the following processes is likely to have the greatest fume generation rate?
a) SMAW
b) SAW
c) FCAW - Correct Answer - c) FCAW
Industrial hygienists often refer to allowable exposure to fumes in terms of the TLV- TWA. What do the letters TWA stand for and what do they mean? - Correct Answer - Time Weighted Average. Average concentration over 8 hour day / 40 hour work week. 3 / 4
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True or False? The TLV for welding fume is 5mg/m3. It does not matter what is in the fume as long as the concentration is below this level. - Correct Answer - False. The components, either individually or as a group, could exceed their TLV levels even though the total fume level is below 5mg/m3.
What label/class?
Materials such as carbon dioxide and argon that are gases at room temperature (20C) and are kept under pressure. - Correct Answer - Class A- Compressed Gas (e.g.Welding gases in cylinders)
What label/class?
Materials that will ignite and continue to burn when exposed to a flame. A flammable liquid is one with flash point less than 27.8C (100F) and a combustible liquid is one with a flash point greater than 37.8C.
The flashpoint is the minimum temperature at which the liquid gives off enough vapour to ignite; the lower the flash point, the greater the fire hazard. - Correct Answer - Class B- Flammable and Combustible (e.g. Flammable: Gasoline, ethyl alcohol, acetylene;
Combustible: Kerosene, creosote, diesel fuel)
What label/class?
Materials, such as oxygen or potassium chlorate, which will cause another to burn. - Correct Answer - Class C- Oxidizing. (e.g. oxygen or potassium chlorate)
What label/class?
Materials causing immediate serious toxic effectrs when taken into the body? - Correct Answer - Class D- Poisonous and Biohazardous Infectious (e.g. Carbon monoxide)
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