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CET study guide questions with
complete solutions
8.33 meters is the full wavelength in air for what RF frequency? ✔✔36 MHz
Decimal 164 would appear as what in binary? ✔✔ 10100100
A resistor has color stripes yellow, violet, violet, silver. It is? ✔✔470 MegOhm +/- 10%
What is the total capacitance of three capacitors valued at 100uf, 100uf and 50uf when connected in series? ✔✔25 pf
What is the ripple frequency of a full wave single phase bridge rectifier operated at 60 Hz? ✔✔120 Hz
What emits a voltage when heated or cooled? ✔✔Thermocouple
Adding the binary numbers 101011 and 001110 will give you what result? ✔✔ 111001
A component that reduces in resistance as it is heated. ✔✔A negative temperature coefficient thermistor
An autotransformer ✔✔has a single winding
A dual trace oscilloscope differs from a single trace in that only the dual trace scope: ✔✔alternates sweeps
If an RF signal Voltage is reduced by 6db it is then : ✔✔half the original size
Applying positive voltage to the P end and negative to the N end of a germanium diode: ✔✔will forward bias it
You would probably prefer a digital VOM over an ordinary analog meter: ✔✔for most accuracy
You should expect the video amplifier in a radar or TV receiver to have a frequency response of: ✔✔0-6 MHzd
Carbon microphones are much like variable: ✔✔resistors
An antenna that is longer than another: ✔✔will have a lower resonant frequency
An 8 bit binary code allows how many logical combinations. ✔✔ 256
An inductor in an electronic circuit: ✔✔resists AC current flow
A printer directly connected to a personal computer would use what kind of connection? ✔✔usb or parallel centronics
The digital method of representing characters by using combinations of zeros and ones is called: ✔✔Binary
AM utilizes signal level variations where FM utilizes : ✔✔Frequency variations
What decimal number is represented by the binary number 01101010? ✔✔ 106
Decimal 50 would appear as what number in Hex? ✔✔ 32
The display of a DMM would probably be: ✔✔LCD
A disadvantage of LCD is: ✔✔Environmental temperature sensitivity
A series DC motor with no load: ✔✔maybe damaged by excessive speed
Which motor maintains a constant speed with changing load? ✔✔Shunt
A small power drill or electric mixer would probably be powered by a ✔✔Series Motor
0 db when referring to audio signals means: ✔✔decibels referenced to 1 milliwatt
If a class A differential amplifier is using only one of its two possible inputs, what will the output shape be? ✔✔Exactly the same as the one input
The average of a full sine wave rectified voltage is : ✔✔.637 X Peak
The ripple frequency for a half wave rectifier operating from 60 Hz electrical power is: ✔✔ 60 HZ
The effective voltage of a 100v Peak-to-peak sine wave is: ✔✔35.35 VAC
A pi filter is an inductor with: ✔✔A capacitor at each end to common
An inductor opposes any change in: ✔✔current
A capacitor opposes any change in: ✔✔voltage
A capacitor will charge to what percent of full charge in one RC time? ✔✔63.
Moving one plate of a capacitor further away from the other will: ✔✔decrease capacitance
The fact that an inductor opposes any change in current is true of: ✔✔AC and DC signals
If you increase the value of a capacitor, the capacitive reactance will: ✔✔decrease
In checking a capacitor to see if it is really shorted, open or leaky: ✔✔you would use the highest ohm meter range.
The capacitor in a power supply capacitive filter: ✔✔Is in parallel with the load
The time required to discharge a capacitor depends on the: ✔✔combination of LRC across its terminals.
With a given filter type, pure filtering is easiest with: ✔✔High frequencies
A power supply whose output voltage does not change whether the load is light or heavy would have what percent of regulation? ✔✔ 0
Solder flux mainly: ✔✔removes oxides on metals to be soldered
Laminations used for the core of a transformer: ✔✔must be insulated from each other
I=1 amp, R=10,000 ohms. What is the value of the voltage? ✔✔10,000 volts
If R=200 ohms and I=.02 amps. What is the value of P(power)? ✔✔.08 watts
Which frequency will have a higher loss when using coaxial cable transmission line? ✔✔1 Ghz
What is a reference antenna that all other antennas with gain are compared to? ✔✔dipole
A high frequency antenna is than a low frequency one. ✔✔is shorter
Standing waves on a transmission cable: ✔✔can be caused by poor termination
Sideband frequencies are produced when an radio carrier frequency is: ✔✔modulated
Doubling the power in a transmitter output is a: ✔✔3 db gain
0 db is what level of received TV signal? ✔✔1000 microVolts
A byte is: ✔✔8 bits
In a 3 input AND gate: ✔✔3 input must be high for a high output
An LCD operates by polarizing the light through filters. The fluid rotates the light: ✔✔ 90 degrees
To test an SCR with an ohmmeter. ✔✔with + to anode and - to cathode, short gate and anode together
Using the Rx100 range and testing between the source and drain of an N channel JFET: ✔✔readings should be equal in both directions
Permanent, non-volatile, non removable data storage in a computer is: ✔✔ROM
What should be used first to clean a corroded plated soldering iron tip? ✔✔flux, cloth and heating
When soldering high voltage connections: ✔✔Leave the terminal with a smooth and rounded covering of solder
Class AB operation of an audio amplifier means that current flows through the active device(tube, transistor,FET,IC) for how many degrees of the input signal wave? ✔✔more than 180 but less then 360
A track on a computer disk is: ✔✔divided into sectors
A PC has conventional RAM and ROM memory area(in a PC it is 0 to 640 kilobytes); upper memory area(640 kilobytes to 1 meg) and extended memory area(above 1 meg). What other names for internal memory types do PCs have? ✔✔Tape Drive
Which video system has the highest resolution? ✔✔XVGA
You would want to use a dual trace oscilloscope to measure: ✔✔signal difference between two points
Common Intermediate Frequencies(IF's) and FM commercial broadcast receivers are: ✔✔ 455 MHz and 10.7MHz
Analog radio receiver signal compression: ✔✔reduces the high frequency received signal amplitude
Coaxial cable line losses at RF frequencies are due to: ✔✔wire resistance, capacitive and inductive reactance
You are troubleshooting audio reproduction equipment and measure the signal to be input into the audio amplifier. What approximate RMS level would you expect the signal to be? ✔✔ 1000 millivolts
The noise level in a radio receiver is generated mostly in the: ✔✔RF section
A "Video Signal" is defined as: ✔✔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: ✔✔Should be discharged to chassis ground, through a suitable resistor
A schematic used in electronic: ✔✔is much like a road map for following signals
High voltage should be discharged before servicing a product. After disabling AC input power, discharge a high voltage power source by: ✔✔draining thru a large value resistor to chassis ground
Which of these would be an important electrical consideration in the use of a transformer? ✔✔The operating frequency
If a 12v product is dissipating 50w, how much load resistance does the device represent? ✔✔2. ohms
An "audio signal" is defined as: ✔✔frequencies in the 20Hz to 15000Hz range
What will cause a generator to produce DC voltage rather then AC? ✔✔the commutator
You suspect the unit has an internal short. To prevent further damage when you apply power, you should: ✔✔insert a low resistance high wattage(100ohm, 10w) resistor in series with the power input.
A ripple counter: ✔✔Is two or more logical flip-flops connected sequentially with the input pulses toggling the first one
When voltage is applied to a capacitor: ✔✔current is maximum at first, then reduces as the capacitor becomes charges.
An electrolytic capacitor in series between the power transformer and the rectifiers in a power supply: ✔✔is part of a voltage doubler circuit
Information travels through optic fiber via the flow of: ✔✔photons
A technician must be knowledgeable about "ESD": ✔✔because static discharge can destroy many components.
In a motor, the counter-emf voltage induced in the armature the source current. ✔✔subtracts from
One significant difference between a TV antenna and a CB antenna would be: ✔✔TV is polarized horizontal while CB is vertical
"Switching power supplies": ✔✔sometimes called DC to DC converters, maybe operated of AC or DC sources
Which of these would you likely find in a DC motor speed control circuit? ✔✔An op-amp
A transformer on a schematic has two leads connected to the primary and three to the secondary, one to each end and one in the middle. This is an: ✔✔center tapped secondary transformer
The 9 pin DB9 connector serial port on a PC is commonly called the: ✔✔RS232 standard
Three capacitors, of 470pf, 560pf and .47pf are in parallel with each other. The total is: ✔✔1030.47pf
Ohm's law provides equations relating to: ✔✔Volts, amps and resistance
A power source such as a generator or battery might be compared to what component in a water supply system? ✔✔A water tank
Which of these is a good indication of the quality of an analog meter? ✔✔The ohms per volt rating
The vertical axis of an oscilloscope display is also called the: ✔✔Y axis
If you increase the value of an inductor, the inductive reactance will: ✔✔increase
Which would least likely be a high-voltage(above 1000V) capacitor? ✔✔electrolytic
