CWB 2 All Module Exams Questions and Answers(A+ Solution guide)

CWB 2 All Module Exams A Plasma is: A) A gas made up of positive ions and free electrons B) A liquid used to reduce adherence of spatter C) The mai n component in an inverter power source D) Always present in an electrical circuit - AnswerA) A gas made up of positive ions and free electrons To increase melting rate (burn -off rate) in the shielded metal arc welding (SMAW) process, which polarity shoul d be used? A) DCEP B) ACEP C) DCEN D) ACEP - AnswerC) DCEN Which type of welding power source is used for the SMAW process? A) Constant Current B) Constant Voltage C) Pulsed Current D) Pulsed Voltage - AnswerA) Constant Current The purpose of a drooping welding power source is to produce: A) Constant voltage regardless of the current demand B) Constant arc length regardless of current C) Nearly constant current regardless of voltage fluctuations B) Low open circuit voltage - AnswerC) Nearly constant current regardless of voltage fluctuations A self -regulating welding arc is produced by a: A) Constant current power source with a constant speed wire feed system B) Constant voltage power source with a voltage sensing wire feed sys tem C) Constant current power source D) Constant voltage power source with a constant speed wire feed system - AnswerD) Constant voltage power source with a constant speed wire feed system Short circuit current is determined by the: A) Voltage in the cir cuit B) Static characteristic of the power source C) Position of welding D) Skill of the welder - AnswerB) Static characteristic of the power source A Transformer is a device that: A) Transforms AC to DC B) Works only to change a DC voltage C) Changes th e value of an AC voltage but does not change the frequency D) Is made from a semiconductor - AnswerC) Changes the value of an AC voltage but does not change the frequency A Rectifier is a device that converts: A) DC current to AC current B) AC Current to a high value DC current C) DC current to a high value DC current D) AC current to DC current - AnswerD) AC current to DC current Microprocessor controls are used in the more modern welding power sources to: A) Provide more sophisticated levels of control for the welding system B) Allow welding variables to be stored for use later C) Provide feedback control D) All of the above - AnswerD) All of the above Inverter welding power sources provide increased control over the welding arc becaus e they: A) Utilize feedback control B) Can respond very quickly to correct any changed in the welding circuits C) Can utilize advanced pulsed waveforms to allow out of position welding using spray transfer D) All of the above - AnswerD) All of the above It would be correct to say: A) Expansion and contraction are proportional to the dimensions of the heated area B) When a bar is heated under restraint, its stress relieves itself as it cools C) Slow cooling of a heated area will provide the greatest amoun t of shrinkage D) When metal is heated it expands, but it does not shrink back to its original size when it cools - AnswerA) Expansion and contraction are proportional to the dimensions of the heated area To reduce the amount of angular distortion you sho uld: A) Increase the travel speed B) Reduce the angle of preparation C) Pre -heat the metal