Line D Exam Flashcards
For an Arc current of under 60 A, what is the MINIMUM protective shade number?
a. 7
b. 8
c. 10
d. 11
a. 7
For arc current UNDER 60 A, the MINIMUM protective shade is 7.
For an Arc current of 120 A, what is the MINIMUM protective shade number?
a. 7
b. 8
c. 10
d. 11
b. 8
For an arc current between 60-180 A, the MINIMUM protective shade is 8
For an Arc current of 190 A, what is the MINIMUM protective shade number?
a. 7
b. 8
c. 10
d. 11
c. 10
For an arc current between 160-250 the MINIMUM protective shade is 10.
For an Arc current of 310 A, what is the MINIMUM protective shade number?
a. 7
b. 8
c. 10
d. 11
d. 11
For an arc current of 250-550 A, the MINIMUM protective shade is 11
True or false. The employer is responsible to ensure workers are trained in the care and use of personal protective equipment PRIOR to its use.
a. True
b. False
a. True
What is the primary function of the shielded metal arc welding (SMAW) process?
a) Generating electricity
b) Melting the surfaces of the joint and the metal electrode
c) Cooling and solidifying molten metal
d) Providing a protective shield around the weld joint
b) Melting the surfaces of the joint and the metal electrode
How is the filler metal introduced into the weld joint in SMAW?
a) It is injected into the joint before the arc is established then carried through
b) It is carried across the arc from the workpiece to the electrode
c) It is preheated and then applied manually onto the joint
d) It is automatically fed into the arc from a separate feeding mechanism
b) It is carried across the arc from the workpiece to the electrode
What happens to the metal electrode and the base metal during the SMAW process?
a) They are vaporized by the heat of the arc
b) They are cooled rapidly by a water-cooling system
c) They are gradually melted by the arc
d) They are shielded from the arc by a gas flow
c) They are gradually melted by the arc, [providing a moving pool of molten metal]
What knowledge is essential to understand the SMAW process completely
a) Advanced mathematics
b) Fundamentals of chemistry
c) Basics of electricity and welding machine operation
d) Principles of mechanical engineering
c) Basics of electricity and welding machine operation
What is voltage in an electrical system often compared to in other systems?
a) Temperature
b) Force
c) Velocity
d) Color
b) Force
Which term is sometimes used interchangeably with voltage?
a) Amperage
b) Resistance
c) Electromotive force
d) Capacitance
c) Electromotive force [EMF]
What unit is used to measure electrical potentials?
a) Amperes
b) Watts
c) Volts
d) Ohms
c) Volts
What is the essential difference between an alternator and a generator?
a) Their physical size
b) Their weight
c) The way they produce voltage
d) The color of their casing
c) The way they produce voltage
In a conductive circuit, which terminal of the power source is the source of electrons?
a) Positive (+)
b) Negative (-)
c) Ground
d) Neutral
b) Negative (-)
What does OCV stand for in the context of SMAW?
a) Overheating Current Voltage
b) Open Circuit Voltage
c) Overloaded Current Voltage
d) Ohm’s Circuit Variation
b) Open Circuit Voltage
Where does current flow from and to?
a) From positive to negative terminal
b) From negative to positive terminal
c) From both terminals simultaneously
d) From the center of the source to the outer casing
b) From negative to positive terminal
What property of copper wire makes it suitable for use in electrical circuits?
a) High resistance
b) Low resistance
c) High capacitance
d) Low capacitance
b) Low resistance
The low resistance makes it a great conductor because it provides “low resistance” to the passage of current.
What is the role of the negative (-) labeled terminal on the output connections of a power source?
a) It attracts electrons from the circuit
b) It repels electrons from the circuit
c) It is a source of electrons for the circuit
d) It is a sink for electrons in the circuit
c) It is a source of electrons for the circuit
Electrons move from the negative side of the power source, travel through the circuit, and reach the positive side. The negative (-) labeled terminal on the output of the power source is where electrons come from.
In SMAW what is OCV (open circuit voltage) used to measure?
a) Voltage drop during welding process
b) Current flow during welding process
c) Voltage between electrode and work lead not during welding process
d) Resistance of the welding cables nut during the welding process
c) Voltage between electrode and work lead not during welding process
Which of the following describes the polarity of direct current electrode negative?
a) reverse polarity
b) straight polarity
b) Straight polarity
[“Straight” people are “N”aked]
Which of the following describes the polarity of direct current electrode positive?
a) reverse polarity
b) straight polarity
a) reverse polarity
In welding, how can the direction of DC current be changed?
a) By altering the power supply voltage
b) By changing the type of electrode
c) By using a polarity switch or reconnecting the cables
d) By adjusting the welding speed
c) By using a polarity switch or reconnecting the cables
What happens to the polarity of AC (alternating current)?
a) It remains constant throughout the welding process
b) It changes every quarter cycle
c) It changes every half cycle
d) It changes randomly
c) It changes every half cycle
What is the relationship between arc length and changes welding current?
1.”Short arc length corresponds to low welding current”
2. “Short arc length corresponds. to high welding current”
3. “Long arc length corresponds to low welding current”
4. “Long arc length corresponds to high welding current”
a) 2
b) 3
c) 4&1
d) 2&3
d) 2&3
With a SHORT arc length, you achieve a high welding current and a low arc voltage.
With a LONG arc length, you achieve a low welding current and a high arc voltage.
The relationship between the voltage and the current produced by a welding power source is usually expressed in the form of a graph that shows the volt-ampere curve.