ATT COMP COMPREHENSIVE EXAM QUESTIONS AND
SOLUTIONS MARKED A+
✔✔what troubleshooting step is used to localize a problem? - ✔✔calculate and
measure
✔✔if you measure a component equal to applied voltage it is....... - ✔✔open
✔✔an open component or wire will measure..... - ✔✔Max or infinite resistance
✔✔current is measured in an open circuit when the meter leads are placed...... -
✔✔across the open
✔✔components with no voltage drop are...... - ✔✔short
✔✔they shorted component wire will measure...... - ✔✔minimum resistance
✔✔What fault provides no resistance to current flow? - ✔✔a short
✔✔what causes resistance to go up or down? - ✔✔changed value
✔✔what causes current to stop? - ✔✔an open
✔✔how many cycles per second is 60 hertz - ✔✔60
✔✔what is the formula for finding a period of a wavelength? - ✔✔T= 1÷f
✔✔what is the. Of a 20 Hertz sine wave? - ✔✔0.05 seconds
✔✔what is the period of AC power at 60 hertz? - ✔✔0.017 seconds
✔✔what is the period of 80 kilohertz? - ✔✔12.5 microseconds
✔✔how do you find wavelength? - ✔✔Lambda = 300 X 10^6 ÷ f
✔✔What is the wavelength of a 20 kilohertz sine wave? - ✔✔15000 meters
✔✔what is the wavelength of a 700 kilohertz frequency? - ✔✔428.6 meters
✔✔how do you find total resistance in a series circuit? - ✔✔Add all the resistances
together
✔✔how do you find Peak voltage? - ✔✔Vpp ÷ 2
, ✔✔how do you find vrms? - ✔✔0.707 X Vp
✔✔what quantity cannot be measured directly or derived from oscilloscope? -
✔✔resistance
✔✔what value of ac voltage does oscope directly measure? - ✔✔Peak to Peak
✔✔what is the minimum Channel requirement for the display with two waveforms? -
✔✔dual Trace
✔✔what occurs when positive current hits a capacitor plate? - ✔✔it builds up a positive
charge
✔✔step up Transformers produce..... - ✔✔a higher es than ep
✔✔Transformers that has a turn ratio of 7:2..... - ✔✔steps down voltage
✔✔an open in the primary of a transformer.... - ✔✔produces no current in the secondary
✔✔an open in the secondary of a transformer prevents and out voltage in.... - ✔✔the
open secondary
✔✔a partial short in the primary of a transformer.... - ✔✔increase is secondary voltage
✔✔a complete short in the secondary Transformer.... - ✔✔eliminates secondary voltage
✔✔which part of a power supply unit changes pulsating DC to smooth DC? - ✔✔the
filter
✔✔what part of a power supply unit changes AC to pulsating DC? - ✔✔the rectifier
✔✔what section of a power supply unit maintains a constant output voltage? - ✔✔the
regulator
✔✔current flowing through a relays contacts in one direction can only cause what
failure? - ✔✔coned and cratered contacts
✔✔you clean relay contacts with what tool? - ✔✔a burnishing tool
✔✔how do you fix a sealed relay? - ✔✔replace the entire relay
✔✔what is the effect of an open component? - ✔✔prevent current flow
SOLUTIONS MARKED A+
✔✔what troubleshooting step is used to localize a problem? - ✔✔calculate and
measure
✔✔if you measure a component equal to applied voltage it is....... - ✔✔open
✔✔an open component or wire will measure..... - ✔✔Max or infinite resistance
✔✔current is measured in an open circuit when the meter leads are placed...... -
✔✔across the open
✔✔components with no voltage drop are...... - ✔✔short
✔✔they shorted component wire will measure...... - ✔✔minimum resistance
✔✔What fault provides no resistance to current flow? - ✔✔a short
✔✔what causes resistance to go up or down? - ✔✔changed value
✔✔what causes current to stop? - ✔✔an open
✔✔how many cycles per second is 60 hertz - ✔✔60
✔✔what is the formula for finding a period of a wavelength? - ✔✔T= 1÷f
✔✔what is the. Of a 20 Hertz sine wave? - ✔✔0.05 seconds
✔✔what is the period of AC power at 60 hertz? - ✔✔0.017 seconds
✔✔what is the period of 80 kilohertz? - ✔✔12.5 microseconds
✔✔how do you find wavelength? - ✔✔Lambda = 300 X 10^6 ÷ f
✔✔What is the wavelength of a 20 kilohertz sine wave? - ✔✔15000 meters
✔✔what is the wavelength of a 700 kilohertz frequency? - ✔✔428.6 meters
✔✔how do you find total resistance in a series circuit? - ✔✔Add all the resistances
together
✔✔how do you find Peak voltage? - ✔✔Vpp ÷ 2
, ✔✔how do you find vrms? - ✔✔0.707 X Vp
✔✔what quantity cannot be measured directly or derived from oscilloscope? -
✔✔resistance
✔✔what value of ac voltage does oscope directly measure? - ✔✔Peak to Peak
✔✔what is the minimum Channel requirement for the display with two waveforms? -
✔✔dual Trace
✔✔what occurs when positive current hits a capacitor plate? - ✔✔it builds up a positive
charge
✔✔step up Transformers produce..... - ✔✔a higher es than ep
✔✔Transformers that has a turn ratio of 7:2..... - ✔✔steps down voltage
✔✔an open in the primary of a transformer.... - ✔✔produces no current in the secondary
✔✔an open in the secondary of a transformer prevents and out voltage in.... - ✔✔the
open secondary
✔✔a partial short in the primary of a transformer.... - ✔✔increase is secondary voltage
✔✔a complete short in the secondary Transformer.... - ✔✔eliminates secondary voltage
✔✔which part of a power supply unit changes pulsating DC to smooth DC? - ✔✔the
filter
✔✔what part of a power supply unit changes AC to pulsating DC? - ✔✔the rectifier
✔✔what section of a power supply unit maintains a constant output voltage? - ✔✔the
regulator
✔✔current flowing through a relays contacts in one direction can only cause what
failure? - ✔✔coned and cratered contacts
✔✔you clean relay contacts with what tool? - ✔✔a burnishing tool
✔✔how do you fix a sealed relay? - ✔✔replace the entire relay
✔✔what is the effect of an open component? - ✔✔prevent current flow
