review Questions - Electrical Principles Flashcards
What is another term for DCEP?
- straight polarity
- direct current electromotive potential
- reverse polarity
- alternating current positive
reverse polarity
to initiate an arc requires:
1. high current
2. high voltage
3. high inductance
4. high resistance
high voltage
how much current will flow through a resistance of 200 ohms when 100 volts is applied?
1. 0.5 amps
2. 5.0 amps
3. 2.0 amps
4. 20 amps
0.5 amps
A generator consists of rotating conductors in a stationary magnetic field and alternator consists of a rotating magnetic field inside the conductor wings.
- true
- false
true
when using SMAW, the welding cables represent a series circuit. where should voltage be measured?
- at the power source
- anywhere in the circuit
- from the electrode holder to the work lead
- through the contact tip
from the electrode holder to the work lead
What type of power supply is required for GTAW?
- constant voltage
- high frequency
- variable current
- constant current
constant current
One of the simplest ways of controlling the output of a welding transformer is to change the efficiency of coupling. How can this be done?
- slide a piece of wood between the primary and the secondary
- design the transformer with either a moving core or moving primary coils
- design the transformer with a number of taps to select different output curves
- use the timed firing of SCR’s to control total conduction time
design the transformer with either a moving core or moving primary coils
what is the term for voltage measured across the output terminals of a welding machine when no current is being drawn?
- diode voltage
- operating voltage
- open circuit voltage
- terminal voltage
open circuit voltage
Which metal has the lowest electrical resistivity?
- aluminum
- tungsten
- copper
- iron
copper
A transformer with more windings in the primary than the secondary is what kind of transformer?
- step up
- isolator
- step down
- inverter
step down
A transformer works on what type of current?
- DCEP
- DCEN
- AC
- DC
AC
What is the unit of measure for electomotive force?
- amp
- volt
- ohm
- flux
- hertz
volt
what is the unit of measure for frequency?
- amp
- volt
- ohm
- flux
- hertz
hertz
in the constant voltage output system, increasing tip to work distance increases the resistance in the power circuit. What is the effect on current flow?
- no effect on current
- increase the current
- decreases the current
- pulsing of current
decreases the current
how much current will flow through a resistance of 50 ohms when 25 volts is applied?
- 0.2 amps
- 0.5 amps
- 2 amps
- 5 amps
0.5 amps
Which type of power is best suited for manual welding?
- constant voltage
- alternating current
- high frequency start
- constant current
constant current
An arc welding power source which has an unchanging potential (voltage) is called what?
- constant current
- alternating current
- direct current
- constant voltage
- variable voltage
constant voltage
What is the open circuit voltage (OCV)?
- Voltage measured across the arc.
- voltage input frommain supply
- voltage drop through the cables
- voltage duty cycle rating
- votage potential without power flowing
votage potential without power flowing
Resistance is measured in which of the following terms?
- hertz
- volts
- amps
- ohms
ohms
A rectifier is a device that is used to?
- convert DC to AC
- convert AC to DC
- switch polarity from negative to positive
- to step down high voltage to low voltage
convert AC to DC
batteries produce what type of current?
- DC
- AC
- AC orDC
- OCV
DC
Arc Blow caused by magnetic forces in the current flow can be greatly reduced or eliminating by?
- peening between weldswith a hammer
- relocating the location of the work lead
- switching weld current to AC
- using higher amperages than normal to overcome magnetic field
switching weld current to AC
Residential power in Canada is supplied at what value?
- 120v and 240v 3 phase
- 575v sisingle phase
- 460v 3 phase
- 120v to 240v single phase
120v to 240v single phase
How long can a welding machine rated at 60% Duty Cycle operating continuously at its rated duty output?
- 6 minutes out of 10 minutes
- 36 minutes out of 60 minutes
- 60 minutes out of 100 minutes
- continuously for 60 minutes
6 minutes out of 10 minutes