Chapter 9 SMAW

Question 1

What is the temperature of the arc in SMAW?

Answer 1

Can be over 9000F (500C)

Question 2

What is polarity?

Answer 2

The direction in which the electrons flow

Question 3

Power sources produce which two types of currents?

Answer 3

AC (alternating current) and DC (direct current)

Question 4

What is DCEN (direct current electrode negative)?

Answer 4

The arc welding method in which direct current flows from the electrode which is negative to the work piece.

Question 5

What is DCEP (direct current electrode positive)

Answer 5

The arc welding method in which direct current flows from the work piece which is negative to the electrode.

Question 6

What is a benefit of DCEP?

Answer 6

Produces deeper penetration than DCEN

Question 7

When would DCEN be useful?

Answer 7

When using thin metals because it doesn’t penetrate deeply.

Question 8

What is a benefit of DCEN

Answer 8

It can deposit a filler metal at a faster rate than DCEP

Question 9

Alternating current (AC) operates at ______ cycles per second

Answer 9

60 cycles per second

Question 10

A ______________ is a set of repeating events such as the flow and reversal of flow in an electric circuit.

Answer 10

cycle

Question 11

Alternating current flows in one direction for _______ of a second, then reverses its direction and flows for ______ second to form one complete cycle.

Answer 11

1/120 sec and 1/120 sec for a total time of 1/60 sec

Question 12

Define constant current (CC)

Answer 12

Term used for arc welding machines produce a nearly constant current even though the voltage may vary

Question 13

Define constant voltage (CV)

Answer 13

Term used for arc welding machines that alter currents as needed to produce a nearly constant voltage

Question 14

what is another term for droopers or droop curve machines?

Answer 14

CC welding machines

Question 15

Which of the following welding machines does not produce AC and DC welding currents?

Answer 15

Transformer

Question 16

Why are welding transformers sometimes called step down transformers?

Answer 16

Because the voltage is reduced

Question 17

Define primary current

Answer 17

Alternating current supplied to the input side of a transformer

Question 18

Define secondary current

Answer 18

The current coming out of a transformer

Question 19

What is duty cycle?

Answer 19

It is a rating that indicates how long a welding machine can be used at its maximum output current without damaging it

Question 20

A welding machine with a 60% duty cycle is based on a ______ minute time period

Answer 20

6-10 minute

Question 21

_____________ is the voltage of the welding machine when it is on, but is not being used.

Answer 21

Open-circuit voltage (OCV)

Question 22

The electric cable that connects the electrode holder to a welding machine is called the _______________

Answer 22

electrode lead

Question 23

The ____________ is the electric cable that connects the base metal to the welding machine

Answer 23

workpiece lead

Question 24

What determines the size of the lead?

Answer 24

• amount of the current being used
• distance/length of lead

Question 25

What shouldn’t you do to attach a workpiece lead to a workpiece or worktable?

Answer 25

Weld the workpiece lead to the table

Question 26

What filter lens number should be used when welding with a 3/16” SMAW electrode?

Answer 26

12

Question 27

The vertical line in a bevel-groove and fillet weld symbols is always drawn at the _______ side of the weld symbol

Answer 27

left