ATT COMP ACTUAL FINAL PAPER QUESTIONS AND
SOLUTIONS MARKED A+
✔✔What is the formula for finding a period of a wavelength? - ✔✔T = 1/f
✔✔What is the period of a 100 Hz sine wave? - ✔✔0.01
✔✔Formula for a wavelength? - ✔✔(300 X 10^6)/f
✔✔What quantity cannot be measured directly or derived from oscilloscope? -
✔✔Resistance
✔✔A/an ___________ is a component that has the ability to concentrate a magnetic
field. - ✔✔inductor
✔✔What are the three types of inductors? - ✔✔Air core, iron core, and variable.
✔✔Inductance - ✔✔basic unit is Henry (H, big so usually mH), ability of conductor to
induce(generate) V when cut by mag F.
✔✔What factors determine the amount of inductance? - ✔✔Number of turns of wire,
distance between windings, cross sectional area of core, and permeability of core.
✔✔What is a capacitor made of? - ✔✔Two parallel plates separated by a dielectric.
✔✔What are the types of capacitors? - ✔✔Non polarized, electrolytic, and variable.
✔✔What is capacitance? - ✔✔The ability of a conductor to store energy in the form of
electrically separated charges.
✔✔What factors affect capacitance? - ✔✔Plate size, distance between plates, and
dielectric material.
✔✔What occurs when positive current hits a capacitor plate? - ✔✔It builds up a positive
charge.
✔✔Transistors - ✔✔Control a large current with a small current.
✔✔Emitter - ✔✔Heavily doped so it emits larger # of current carriers inside semi
conductive material.
✔✔Base - ✔✔Very thin and lightly doped, allows most current carriers to pass between
emitter to collector.
, ✔✔Collector - ✔✔Moderately doped, largest area, dissipates heat. Receives most
current carriers.
✔✔What two types of signals applied to transistors? - ✔✔Input and bias.
✔✔An open in the primary of a transformer won't do what? - ✔✔Produce current in the
secondary.
✔✔An open in the secondary of a transformer prevents an output voltage in _____
_________ ________________. - ✔✔the open secondary
✔✔A partial short in the primary of the transformer will _____________ secondary
voltage. - ✔✔Increase
✔✔A complete short in the secondary transformer will ____________ secondary
voltage. - ✔✔eliminate
✔✔Current flowing through a relays contacts in one direction can only cause what
failure? - ✔✔Coned and cratered contacts.
✔✔What tool should be used to clean relay contacts? - ✔✔A burnishing tool.
✔✔How do you fix a sealed relay? - ✔✔Replace the entire relay.
✔✔What does quiescent mean? - ✔✔Inactive; at rest, but ready to operate.
✔✔Power supplies does what? - ✔✔Converts AC power to DC power.
✔✔A power supply contains five sections. What are they? - ✔✔Input, rectifier, filter,
regulator and protection.
✔✔Power supply input - ✔✔Applies AC signal.
✔✔Power supply rectifier - ✔✔Converts AC to pulsating DC.
✔✔Power supply filter - ✔✔Changes pulsating DC to smooth DC.
✔✔Power supply regulator - ✔✔Maintains output voltage.
✔✔Power supply protection - ✔✔Prevents damage to power supply if load shorts.
✔✔Which two parts of a power supply are optional? - ✔✔Regulator and protection.
SOLUTIONS MARKED A+
✔✔What is the formula for finding a period of a wavelength? - ✔✔T = 1/f
✔✔What is the period of a 100 Hz sine wave? - ✔✔0.01
✔✔Formula for a wavelength? - ✔✔(300 X 10^6)/f
✔✔What quantity cannot be measured directly or derived from oscilloscope? -
✔✔Resistance
✔✔A/an ___________ is a component that has the ability to concentrate a magnetic
field. - ✔✔inductor
✔✔What are the three types of inductors? - ✔✔Air core, iron core, and variable.
✔✔Inductance - ✔✔basic unit is Henry (H, big so usually mH), ability of conductor to
induce(generate) V when cut by mag F.
✔✔What factors determine the amount of inductance? - ✔✔Number of turns of wire,
distance between windings, cross sectional area of core, and permeability of core.
✔✔What is a capacitor made of? - ✔✔Two parallel plates separated by a dielectric.
✔✔What are the types of capacitors? - ✔✔Non polarized, electrolytic, and variable.
✔✔What is capacitance? - ✔✔The ability of a conductor to store energy in the form of
electrically separated charges.
✔✔What factors affect capacitance? - ✔✔Plate size, distance between plates, and
dielectric material.
✔✔What occurs when positive current hits a capacitor plate? - ✔✔It builds up a positive
charge.
✔✔Transistors - ✔✔Control a large current with a small current.
✔✔Emitter - ✔✔Heavily doped so it emits larger # of current carriers inside semi
conductive material.
✔✔Base - ✔✔Very thin and lightly doped, allows most current carriers to pass between
emitter to collector.
, ✔✔Collector - ✔✔Moderately doped, largest area, dissipates heat. Receives most
current carriers.
✔✔What two types of signals applied to transistors? - ✔✔Input and bias.
✔✔An open in the primary of a transformer won't do what? - ✔✔Produce current in the
secondary.
✔✔An open in the secondary of a transformer prevents an output voltage in _____
_________ ________________. - ✔✔the open secondary
✔✔A partial short in the primary of the transformer will _____________ secondary
voltage. - ✔✔Increase
✔✔A complete short in the secondary transformer will ____________ secondary
voltage. - ✔✔eliminate
✔✔Current flowing through a relays contacts in one direction can only cause what
failure? - ✔✔Coned and cratered contacts.
✔✔What tool should be used to clean relay contacts? - ✔✔A burnishing tool.
✔✔How do you fix a sealed relay? - ✔✔Replace the entire relay.
✔✔What does quiescent mean? - ✔✔Inactive; at rest, but ready to operate.
✔✔Power supplies does what? - ✔✔Converts AC power to DC power.
✔✔A power supply contains five sections. What are they? - ✔✔Input, rectifier, filter,
regulator and protection.
✔✔Power supply input - ✔✔Applies AC signal.
✔✔Power supply rectifier - ✔✔Converts AC to pulsating DC.
✔✔Power supply filter - ✔✔Changes pulsating DC to smooth DC.
✔✔Power supply regulator - ✔✔Maintains output voltage.
✔✔Power supply protection - ✔✔Prevents damage to power supply if load shorts.
✔✔Which two parts of a power supply are optional? - ✔✔Regulator and protection.
