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8.33 meters is the full wavelength in air for what RF frequency? - correct answer ✔✔36 MHz Decimal 164 would appear as ________ in binary? - correct answer ✔✔ 10100100 A resistor has color stripes yellow, violet, violet, silver. It is: - correct answer ✔✔470 MegOhm +/- 10% what is the total capacitance of three capacitors valued at 100pf, 100pf, and 50pf when connected in a series? - correct answer ✔✔25 pf what is the ripple frequency of a full wave single phase bridge rectifier operated at 60Hz? - correct answer ✔✔120Hz When heated or cooled, a ________emits a voltage. - correct answer ✔✔theromcouple Which wire size is physically largest? - correct answer ✔✔# Adding the binary numbers 101011 and 001110 will give you what result? - correct answer ✔✔ 111001 A component that reduces in resistance as it is heated: - correct answer ✔✔Is a negative temperature coefficient thermistor An autotransformer: - correct answer ✔✔has a single winding A dual trace oscilloscope differs from a single trace in that only the dual trace scope: - correct answer ✔✔alternates sweeps
If an RF signal voltage is reduced by 6 dB, it is then: - correct answer ✔✔half the original size Applying positive voltage to the P end and negative to the N end of a germanium diode: - correct answer ✔✔will forward bias it You would probably prefer a digital VOM over an ordinary analog meter: - correct answer ✔✔for most accuracy You should expect the video amplifier in a radar or TV receiver to have a frequency response of: - correct answer ✔✔0-6 MHz The radio communication mode that utilizes the basic frequency and one of the side bands: - correct answer ✔✔is called "SSB" When using fiber optics to transfer a signal, the light must: - correct answer ✔✔Enter the "cone of acceptance" The energy stored in a coil is measured in: - correct answer ✔✔Joules The telephone communication term "cellular" refers to: - correct answer ✔✔small geographic areas covered by each base station. Integrated Circuit failures often exhibit: - correct answer ✔✔open or short conditions Which of these would you normally choose to cause an LED to light? - correct answer ✔✔3 V DC A capacitor (3/8" x 1/8" ceramic or mica) marked 47K is: - correct answer ✔✔47pf+/- 10% A digital storage oscilloscope: - correct answer ✔✔uses micro processing and memory to allow close analysis of signals; is specially designed for analyzing digital signals; converts analog input signals to a digital display
A small power drill or electrics mixer would probably be powered by a/an ______ motor. - correct answer ✔✔series The rotor in an induction motor is not connected to AC or DC power. - correct answer ✔✔True 0 dBm, when referring to audio signals means: - correct answer ✔✔decibels referenced to 1 milliwatt If a class A differential amplifier is using only one of its two possible inputs, what will the output signal shape be? - correct answer ✔✔exactly the same as the one input voltage is: - correct answer ✔✔potential difference between two points _______ is a term describing many op-amp circuits. - correct answer ✔✔Inverting The gain of an op-amp is inversely related to band width as input frequency increases. - correct answer ✔✔Always The audio detector circuit in an AM radio most commonly is a: - correct answer ✔✔Diode A differential amplifier with two identical in phase signals on the inputs will have an output __________.
- correct answer ✔✔of zero A free running oscillator is also called a monostable multivibrator. - correct answer ✔✔false A fuse which has its fusible wire wrapped around an insulator is: - correct answer ✔✔a slo-blo type fuse The power transformer in a power supply: - correct answer ✔✔might step voltages up or down Which of the below would be considered "basic" components of a non switching power supply? - correct answer ✔✔filter, rectifier, transformer
The average of a full sine wave rectified voltage is: - correct answer ✔✔.637 x peak The ripple frequency for a half wave rectifier operating from 60 Hz electrical power is: - correct answer ✔✔60 Hz The effective voltage of a 100V peak to peak sine wave is: - correct answer ✔✔35. A pi filter is an inductor with: - correct answer ✔✔a capacitor at each end to common An inductor opposes any change in: - correct answer ✔✔current A capacitor opposes any change in: - correct answer ✔✔voltage A capacitor will charge to what percent of full charge in one RC time? - correct answer ✔✔63. Moving one plate of a capacitor further away from the other will: - correct answer ✔✔decrease capacitance The fact than an inductor opposes any change in current is true of: - correct answer ✔✔AC and DC signals If you increase the value of a capacitor, the capacitive reactance will: - correct answer ✔✔decrease In checking a capacitor to see if it is shorted, open or leaky, you would use the ________Ohm meter range. - correct answer ✔✔Highest The capacitor in a power supply capacitive filter: - correct answer ✔✔is in parallel with the load
Laminations used for the core of a transformer: - correct answer ✔✔must be insulated from each other. I=1 amp, R=10,000 ohms. What is the value of voltage? - correct answer ✔✔10,000 volts If R=200 ohms and I=.02 amps. What is the value of P (power). - correct answer ✔✔.08 watts Which frequency will have a higher loss when using coaxial cable transmission line? - correct answer ✔✔1 GHz A __________ is a reference antenna that all other antennas with gain are compared to. - correct answer ✔✔Dipole A high frequency antenna ________ than a low frequency one. - correct answer ✔✔is shorter Standing waves on a transmission cable: - correct answer ✔✔can be caused by poor termination Sideband frequencies are produced when a radio carrier frequency is: - correct answer ✔✔modulated Doubling the power in a transmitter output signal is ______ dB gain. - correct answer ✔✔ 3 0 dBm V is what levle of received TV signal? - correct answer ✔✔1000 microvolts A byte is: - correct answer ✔✔8 bits In a 3 input AND gate: - correct answer ✔✔3 input must be high for a high output An LCD operates by polarizing the light through filters. The fluid rotates ____________ degrees. - correct answer ✔✔ 90
To test an SCR with an ohmmeter: - correct answer ✔✔With + to anode and - to cathode, short gate and anode together. Should go from near "open" to near "short." Using the R x 100 range and testing between the source and drain of an N channel JFET: - correct answer ✔✔readings should be equal in both directions With + voltage to drain or source and a - voltage to the gate on an N channel JFET, internal resistance of the JEFT will be: - correct answer ✔✔high Which is LEAST likey to cause ESD damage to a MOSFET? - correct answer ✔✔flux A logic probe: - correct answer ✔✔indicates high and low voltage conditions In a typical electrical generator, a small AC voltage applied to the field windings is able to control the output level of the generator. - correct answer ✔✔false When working with and testing lead acid batteries: - correct answer ✔✔always wear eye protection, never cause a spark and charge in a ventilated room Audio signals, such as the output from DVD players, satellite receivers and preamplifiers, usually are of what amplitude for input to a TV, modulator or other equipment? - correct answer ✔✔1 volt peak to peak Which of these signal parameters does a spectrum analyzer show? - correct answer ✔✔Magnitude and frequency Permanent, non-volatile, non-removable data storage in a computer is: - correct answer ✔✔ROM What should be used first to clean a corroded plated soldering iron tip? - correct answer ✔✔Flux, cloth after heating
The fast charging rate for a NiCad or Ni-MH battery should not exceed _______% of its AHr, or ampere hour rating? - correct answer ✔✔ 10 Which one of the following in a PC would be part of disk operations? - correct answer ✔✔SATA or IDE controller An LED: - correct answer ✔✔can be used as a fiber optic signal source A dual trace oscilloscope may have: - correct answer ✔✔a Z input for intensity modulation The gain of an-amp connected as an inverting amplifier is determined by the external _______. - correct answer ✔✔feedback and input resistors Diodes are made from one type of material. - correct answer ✔✔false Which propagation condition would be significant for UHF signal to be received at a distance of 500 miles? - correct answer ✔✔Tropospheric ducting A three input NAND has two low inputs and one high input. The output is: - correct answer ✔✔High Which of these would be considered a component of "basic" power supply? - correct answer ✔✔Diode rectifer A "video signal" is defined as: - correct answer ✔✔Baseband including visual information. You are servicing a power supply and have disconnected power. It has several 250 uF capacitors connected in parallel. To avoid shock, these capacitors: - correct answer ✔✔Should be discharged to chassis ground, through a suitable resistor. A schematic used in electronic servicing: - correct answer ✔✔is much like a road map for following signals
High voltage should be discharged before servicing a product. After disabling. After disabling AC input power, discharge an HV PS by: - correct answer ✔✔draining through a large value resistor to chassis ground Which of these would be an important electrical consideration in the use of a transformer? - correct answer ✔✔The operating frequency If a 12v product is dissipating 50w, how much load resistance does the device represent? - correct answer ✔✔2.9 ohms An "audio signal" is often defined as: - correct answer ✔✔frequencies in the 20 Hz to 15,000 Hz range _____________ will cause a generator to produce DC voltage rather than AC. - correct answer ✔✔The communtator You supect the unit has an internal short. To prevent further damage when you apply power, you should:
- correct answer ✔✔insert a low resistance high wattage (100 ohm, 10w) resistor in series with the power input A ripple counter: - correct answer ✔✔is two or more logical flip-flops connected sequentially with the input pulses toggling the first When a voltage is applied to a capacitor: - correct answer ✔✔current is maximum at first, then reduces as the capacitor becomes charged An electrolytic capacitor in series between the power transformer and the rectifiers in a power supply: - correct answer ✔✔is part of a voltage doubler circuit Information travels through optic fiber via the flow of: - correct answer ✔✔photons You would most likely prefer an analog VOM over a DMM for: - correct answer ✔✔intermittent functuations
A transformer on a schematic has two leads connected to the primary and three to the secondary, one on each end and one in the middle. This is a - correct answer ✔✔center tapped secondary transformer The 9 pin DB9 connector serial port on a PC is commonly called the ______ standard. - correct answer ✔✔RS Three capacitors, of 470 pf, 560 pf and .47 pf are in parallel with each other. The total is: - correct answer ✔✔1030.47 pf Ohm's law provides equations relating to: - correct answer ✔✔volts, amps, and resistance A power source such as a generator to what component in a water supply system? - correct answer ✔✔A pump Which of these is a good indication of the quality of an analog meter? - correct answer ✔✔the ohms per volt rating The vertical axis of an oscilloscope display is also called the: - correct answer ✔✔Y axis If you increase the value of an inductor, the the inductive reactance will: - correct answer ✔✔increase Which would least likely be a high voltage (above 1,000v) capacitor? - correct answer ✔✔Electrolytic The rechargeable cells currently used in many consumer portable products would be: - correct answer ✔✔Lithium ion A solid stat regulator: - correct answer ✔✔varies conduction to maintain a level output voltage A current carrying conductor is placed in a magnetic field perpendicular to the lines flux. It tends to move in_________ direction to the force of magnetic lines of flux, as determined by flemings left hand rule. - correct answer ✔✔a perpendicular
The antenna used to compare the gain of other antennas is called _______________. - correct answer ✔✔dipole The component that effectively becomes a short when turned on, and is turned off by disconnecting the path from the anode to cathode is the: - correct answer ✔✔silicon controlled rectifier Which of these terms would you most expect to see when referring to types of resistors? - correct answer ✔✔metal film "Microwave," as used in radio electronics, refers to: - correct answer ✔✔1GHz - 100GHz radio frequencies A differential amplifier whose two input signals are equal, but 180 degree out of phase, will have a ___________ output signal. - correct answer ✔✔maximum Which of these can be used to control the output level of a generator? - correct answer ✔✔a small DC voltage applied to the field winding Impedance (Z, in ohms) includes: - correct answer ✔✔Resistance, capacitive reactance and inductive The velocity factor in an RF transmission line is determined by: - correct answer ✔✔the dielectric material between center conductor A fuse, marked 250v, 650ma can be used in circuits with an "open fuse" supply voltage of: - correct answer ✔✔125 volts A thermistor: - correct answer ✔✔changes resistance with temperature When a transformer is designed, what most determines the output voltage from the secondary? - correct answer ✔✔the ratio of primary to secondary turns
VHF or UHF antennas dont use waveguides as feed lines because: - correct answer ✔✔the large dimersions at these wavelengths makes other transmissions lines more practical To trace a logic path, you might use: - correct answer ✔✔A logic pulser Ordinary alpha/numeric information tansmitted by a computer is converted to binary using: - correct answer ✔✔an encoder In electronic devices, what term refers to residual magnetism? - correct answer ✔✔Hysteresis Some variable capacitors are made so that the plates interleave. The capacitance varies as the plates open and close. As they open: - correct answer ✔✔the capacitance decreases In VOM's voltage multiplier resistors are important: - correct answer ✔✔in the voltage scales In a series tuned circuit, to increase the resonant frequency, you need to: - correct answer ✔✔decrease the inductance A MOSFET: - correct answer ✔✔amplifies signal voltage variations Toroid cores are used in transformers for: - correct answer ✔✔concentrating the magnetic flux A PLL, or phase locked loop circuit, contains a VCO, or voltage controlled oscillator. The output of the VCO is a _________. - correct answer ✔✔AC variable frequency signal A variable capacitor depends on: - correct answer ✔✔the plate separation being adjustable While anode and cathode voltages are maintained, the gate level on an SCR drops below the trigger point. What happens? - correct answer ✔✔The SCR stays on
The combination of resistance and reactance which restricts the flow of alternating current is called: - correct answer ✔✔Impedance The output of a thermocouple would most likely be measured in: - correct answer ✔✔millivolts The Z axis on an oscilloscope is: - correct answer ✔✔intensity When soldering transistor or IC chip legs, a _____________ should be used to prevent overheating of the small discrete components. - correct answer ✔✔heat sink clip Which of the below would normally be used for the core of a transformer? - correct answer ✔✔Ferrite The "1" in binary number 100000 carries a weight of: - correct answer ✔✔ 32 You would choose an LCD if you needed: - correct answer ✔✔a low current digital display Germanium diodes: - correct answer ✔✔normally drop about .3 V with forawrd current RF signal propagation what is normally considered "line of sight" would be: - correct answer ✔✔UHF
