Description : Alternating current measured in a transmission line will be a) Peak value b) Average value c) RMS value d) Zero
Last Answer : c) RMS value
Description : _______ is more prevalent in analog signals that have steep slopes or whose amplitudes vary rapidly. A. Peak limiting B. Quantization noise C. Granular noise D. Slope overload
Last Answer : D. Slope overload
Description : The noise output of a resistor is amplified by a noiseless amplifier having a gain of 60 and a bandwidth of 20 kHz. A meter connected at the output of the amplifier reads 1mV RMS. If the bandwidth of the amplifier is reduced to ... does the meter read now? A. 0.5 mV B. 0.5 µV C. 5.0 mV D. 5.0 µV
Last Answer : A. 0.5 mV
Description : An amplifier operating over the frequency range of 455 to 460 kHz has a 200 kΩ input resistor. What is the RMS noise voltage at the input to this amplifier if the ambient temperature is 17˚C ? A. 40 µV B. 4.0 µV C. 400 µV
Last Answer : B. 4.0 µV
Description : In AC circuits, AC meters measure – (1) mean values (2) rms values (3) peak values (4) mean square values
Last Answer : (2) rms values Explanation: Voltages and currents for AC circuits are generally expressed as rms (root mean square) values. For a sine wave, the relationship between the peak and the rms average is: rms value = 0.707 peak value.
Description : In AC circuits, AC meters measure (1) mean values (2) rms values (3) peak values (4) mean square values
Last Answer : rms values
Description : How does a SSB transmitter output power normally expressed? A. Average power B. In terms of peak envelop power C. In terms of peak-to-peak power D. Peak power
Last Answer : B. In terms of peak envelop power
Description : Ammeters and voltmeters used in sinusoidal AC power systems indicate which of the following values of the waveforms measured? A. Peak value B. Root-mean-square value C. Average value D. Maximum value
Last Answer : Answer: B
Description : Which of the following term best described the overload distortion? A. Peak limiting B. Quantization noise C. Granular noise D. Slope distortion
Last Answer : A. Peak limiting
Description : AC voltmeters are generally calibrated to read the ________. A. instantaneous voltage B. average voltage C. RMS voltage D. peak voltage
Last Answer : Answer: C
Description : The voltage at any point in an ac circuit will be a) Peak voltage b) RMS voltage c) Average voltage d) Source voltage
Last Answer : b) RMS voltage
Description : The square of the thermal noise voltage generated by a resistor is proportional to A. its resistance B. its temperature C. the bandwidth over which it is measured D. All of the above
Last Answer : D. All of the above
Description : Indicate the false statement. A. HF mixer are generally noisier than HF amplifiers. B. Impulse noise voltage is dependent on bandwidth C. Thermal noise is independent of the frequency at which is measured. D. Industrial noise is usually of the impulse type.
Last Answer : B. Impulse noise voltage is dependent on bandwidth
Description : Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured ... exist D. All formula referring to random noise are applicable only to the value of such noise.
Last Answer : C. A random voltage across the resistor does not exist
Description : _________ is measured on a circuit when it is correctly terminated but does not have any traffic. A. White noise B. Galactic noise C. Impulse noise D. Atmospheric noise
Last Answer : A. White noise
Description : The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the ... . Reference audio output B. None of these C. Audio frequency response D. Residual noise level
Last Answer : D. Residual noise level
Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone
Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
Description : The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is __________. A. 9/23 B. 23/9 C. 32 dB D. 14 dB
Last Answer : D. 14 dB
Description : The front-end of a television receiver, having a bandwidth of 7Mhz, and operating at a temperature of 27˚C , consists of an amplifier having a gain of 15 followed by a mixer whose gain is 20. The ... equivalent noise resistance for this television receiver. A. 8760 Ω B. 875Ω C. 8.76Ω D. 0.876Ω
Last Answer : B. 875Ω
Description : The first stage of a two-stage amplifier has a voltage gain of 10, a 600 Ω input resistor, a 1600Ω equivalent noise resistance and 27kΩ output resistor. For the second stage, these values are 25, 81kΩ, 19kΩ, and 1MΩ, ... this two stage amplifier. A. 2,518 kΩ B. 2,518 Ω C. 251.8 Ω D. 12,518 Ω
Last Answer : B. 2,518 Ω
Description : Sources of impulse noise induced in communication channels. A. Erroneous digital coding bit caused by an error on a transmission facility B. Transients due to relay operation C. Crosstalk from dc signaling systems D. All of these
Last Answer : D. All of these
Description : What is the proper procedure for suppressing electrical noise in a mobile station? A. Apply shielding and filtering where necessary B. Insulate a all plain sheet metal surfaces from each other C. ... -static spray liberally to all nonmetallic D. Install filter capacitors in series with all dc wiring
Last Answer : A. Apply shielding and filtering where necessary
Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high
Last Answer : D. high
Description : External noise originating outside the solar system A. Cosmic noise B. Solar noise C. Thermal noise D. Lunar noise
Last Answer : A. Cosmic noise
Description : ________ is an electric noise produced by thermal agitation of electrons in conductor and semiconductor. A. External noise B. Internal noise C. Thermal noise D. Flicker
Last Answer : C. Thermal noise
Description : _________ is the random and unpredictable electric signals from natural causes, both internal and external to the system. A. Interference B. Attenuation C. Distortion D. Noise
Last Answer : D. Noise
Description : The random and unpredictable electric signal from natural causes, both internal and external to the system is know as ________. A. Distortion B. Noise C. Attenuation D. Interference
Last Answer : B. Noise
Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.
Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.
Description : Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections ... , or antenna circuits D. DC and RF heating of resistors, causing then to change values.
Last Answer : D. DC and RF heating of resistors, causing then to change values.
Description : Man-made noise is usually from _______. A. transmission over power lines and by ground wave B. sky-wave C. space-wave D. troposphere
Last Answer : A. transmission over power lines and by ground wave
Description : Which is the proper measurement of average power emitted by a pulsed laser? a. Energy x time b. Pulse energy x repetition rate c. Pulse energy / repetition rate d. Peak power x pulse length
Last Answer : b. Pulse energy x repetition rate
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : Referred to as an average power from the radio transmitter supplied to the antenna transmission line taken during one radio frequency cycle under no modulation. A. Carrier power B. Rated power C. Peak envelop power D. Mean power
Last Answer : A. Carrier power
Description : Average power of a radio transmitter supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. A. Peak envelop power B. Rated power C. Carrier power D. Mean power
Last Answer : C. Carrier power
Description : What is sound pressure level if the RMS sound pressure is 100 μbars? A. 114 dB B. 11.4 dB C. 94 dB D. 57 dB
Last Answer : A. 114 dB
Description : ECE Board Exam March 1996 The potential difference between any exposed structured to ground in any electrical installation should not exceed _________ volts RMS. A. 10 B. 45 C. 0 D. 30
Last Answer : B. 45
Description : Define following terms used in A.C. circuits : (i) Cycle (ii) Rms value (iii) Phase difference (iv) Average value
Last Answer : (i) Cycle: A complete set of variation of an alternating quantity which is repeated at regular interval of time is called as a cycle. OR Each repetition of an alternating quantity ... charge as is transferred by the alternating current during the same time under the same conditions.
Description : Column efficiency is measured in terms of number of theoretical plates, which is: A. Inversely related to height equivalent to theoretical plates B. Directly related to the peak width C. Directly related to height equivalent to theoretical plates D. Inversely related to the peak width
Last Answer : Inversely related to height equivalent to theoretical plates
Description : Can I use eurometer calibrated in RMS to measure HWDC in peak?
Last Answer : No
Description : What does the Voltmeter in AC mode show? Is it RMS value or peak value?
Last Answer : Multimeter in AC mode shows RMS value of the voltage or current. Also when it is DC mode it will show the RMS value only.
Description : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V
Last Answer : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V
Description : If the rms voltage drop across a 15 kilt resistor is 16 V, the peak current through the resistor is : - a) 15 mA b) 1.5 mA c) 10 mA d) 1 mA
Last Answer : If the rms voltage drop across a 15 kilt resistor is 16 V, the peak current through the resistor is : - 1.5 mA
Description : The ________ is a function of three values: average data rate, peak data rate, and maximum burst size.
Last Answer : Effective bandwidth
Description : Two tape recorders have signal-to-noise ratios (SNRs) of 25-dB RMS and 35-dB RMS respectively. Which of the SNRs can record and reproduce the widest range of input signals and why?
Last Answer : 35-dB RMS because the highest SNR can always record and reproduce the widest range of input signals.
Description : Most AC voltmeters have an rms scale which is valid only if the input signal being measured is a __ signal.
Last Answer : sinusoidal
Description : In a series RC circuit, 12 V (rms) is measured across.the resistor and 15 V (rms) is measured across the capacitor. The value of rms source voltage is: A. 3 V B. 27 V C. 19.2 V D. 1.9 V
Last Answer : In a series RC circuit, 12 V (rms) is measured across.the resistor and 15 V (rms) is measured across the capacitor. The value of rms source voltage is: 19.2 V
Description : In a half wave rectifier the rms value of AC component of the waves (a) Zero (b) Equal to DC value (c) More than DC value (d) Less than DC value
Last Answer : b) Equal to DC value
Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is
Last Answer : Please show the solution for this question
Description : The polarization of a radio wave: A. Is perpendicular to the electrostatic field of the antenna B. Is the same direction as the electrostatic field of the antenna. C. Is the same direction ... field of the antenna. D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.
Last Answer : B. Is the same direction as the electrostatic field of the antenna.
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.