Description : What is the filter called that passes low frequencies but rejects or attenuates high frequencies?
Last Answer : Low-pass filter, high-frequency discriminator or high-frequency attenuator.
Description : What type filter is used to allow a narrow band of frequencies to pass through a circuit and attenuate all other frequencies above or below the desired band?
Last Answer : Bandpass.
Description : How can intermodulation interference between two transmitters in close proximity reduced or eliminated? A. Through installing a band-pass filter in the antenna feed line B. Through installing terminated circulator ... high driving power D. By installing a low-pass filter in the antenna feed line
Last Answer : A. Through installing a band-pass filter in the antenna feed line
Description : Which of the following filters block FM radio band for TV channels (2 to 13)? A. High-pass filter B. Band reject filter C. Low-pass filter D. Band-pass filter
Last Answer : B. Band reject filter
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 : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna
Last Answer : C. Local oscillator, mixer and RF amplifier
Description : What type filter is used to block the passage of current for a narrow band of frequencies, while allowing current to flow at all frequencies above or below this band?
Last Answer : . Band-reject.
Description : Harmonic suppressor connected to an antenna. A. Low-pass filter B. High-pass filter C. M-derived filter D. Constant-K
Last Answer : A. Low-pass filter
Description : Harmonic suppressor connected to an antenna. A. High pass filter B. Low pass filter C. Tank circuit D. M-derived filter
Last Answer : B. Low pass filter
Description : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison
Last Answer : B. The combination of two signals to produce sum and difference frequencies.
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 : What is the purpose of having a low pass filter in PLL?
Last Answer : *It removes the high frequency components and noise. *Controls the dynamic characteristics of the PLL such as capture range, lock-in range,band-width and transient response. *The charge on the filter capacitor gives a short- time memory to the PLL
Description : Define low pass filter.
Last Answer : A low pass filter allows only low frequency signals upto a certain break point fH to pass through.
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : What band of frequencies do these satellites operate? A. L band B. Ka band C. C band D. Ku band
Last Answer : A. L band
Description : Which band of frequencies used by military for its satellites and radar? A. C band B. X band C. L band D. P band
Last Answer : B. X band
Description : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
Description : Troposheric scatter uses the frequencies in the ________ band. A. VLF B. UHF C. VHF D. UF
Last Answer : B. UHF
Description : ECE Board Exam March 1996 An antenna which is not resonant at a particular frequencies and so can be used over a wide band of frequencies and so can be used over a wide band of frequencies is called A. aperiodic B. boresight C. cassegrain D. top-loaded
Last Answer : A. aperiodic
Description : A mode filter is a device that attenuates specific modes propagating in the core of an optical fiber. What mode propagating along single mode fibers do mode filters eliminate?
Last Answer : Second-order mode.
Description : What do you mean by active filter? State its advantages over passive filter . Define pass band & stop band with respect to filter.
Last Answer : Active Filter: Active Filter is formed by using active element along with the passive components. Advantages of Active filter over Passive filter: High value of pass band gain can be obtained. It is ... pass band. Stop Band Filter: The frequency range which is attenuated is known as stop band.
Description : ECE Board Exam March 1996 Modems are required to connect computer to telephone lines because ___________. A. telephone company rules required them B. the telephone network bandwidth is too high C. none of the above D. the telephone network will pass direct current
Last Answer : D. the telephone network will pass direct current
Description : Define High pass filter.
Last Answer : A low pass filter allows only high frequency signals upto a certain break point fH to pass through
Description : ECE Board Exam March 1996 Crosstalk coupling is ___________. A. dBm (disturbing pair) minus dBm (disturbed pair) B. the difference between readings on a cable pair with a tone and a cable pair without ... a cable C. signals from one circuit that get into another circuit D. All of these are true
Last Answer : D. All of these are true
Description : The satellite communications channels in a transponder are defined by the A. LNA B. bandpass filter C. mixer D. input signals
Last Answer : B. bandpass filter
Description : ______ is the first component of any MATV system to received broadcast signals. A. Receiver B. Antenna C. Filter D. Transmitter
Last Answer : B. Antenna
Description : Atmospheric noise becomes less severe at frequencies A. above 30 MHz B. below 30 MHz C. above 3000 kHz D. below 3000kHz
Last Answer : A. above 30 MHz
Description : Atmospheric noise or static is not a great problem A. at frequencies below 20 MHz B. at frequencies below 5 MHz C. at frequencies above 30 MHz D. at frequencies above 1 MHz
Last Answer : C. at frequencies above 30 MHz
Description : A porous material is far more efficient at high than low frequency absorption. How to improve sound absorption at lower frequencies using this absorber? A. Increase the thickness B. Decrease the thickness C. Mount with and airspace behind D. Both A and C above
Last Answer : D. Both A and C above
Description : ____ system transmits frequency-division-multiplexed voice band signals over a coaxial cable for distances up to 4000 miles. A. T carrier B. X carrier C. L carrier D. F carrier
Last Answer : C. L carrier
Description : Which of the following low noise transistors is commonly used at microwave frequencies? A. MOSFET B. GASFET C. MESFET D. JFET
Last Answer : C. MESFET
Description : ECE Board Exam March 1996 The expander in a companding device provides ___________. A. greater amplification for low signal levels B. less amplification for low signal levels C. greater amplification for high signal levels D. lesser pressure for transmission
Last Answer : B. less amplification for low signal levels
Description : In electronic circuits, what name is given to a frequency discriminating network designed to select or pass certain bands of frequencies with low attenuation and cause very high attenuation to other frequencies?
Last Answer : ANSWER: FILTER
Description : What is the filter called in which the low frequencies do not produce a useful voltage?
Last Answer : High-pass filter, low-frequency discriminator, or low-frequency attenuator.
Last Answer : Passes a certain range of frequency.
Description : A band pass filter is that which
Last Answer : A band pass filter is that which passes signals between two frequency limits
Description : Which band does channel 14 of the television channel belong? A. High VHF band B. EHF band C. UHF band D. Low VHF band
Last Answer : C. UHF band
Description : Channel 7 of the regular television channel belongs to which band? A. Low VHF band B. High VHF band C. Low UHF band D. High UHF band
Last Answer : B. High VHF band
Description : TV channels 2, 4 and 5 are known as ________. A. Mid band UHF B. Low band UHF C. High band VHF D. Low band VHF
Last Answer : D. Low band VHF
Description : The band of light frequencies that are too low to be seen by the human eye ∙ A. Infrared ∙ B. X-rays ∙ C. Visible ∙ D. Ultraviolet
Last Answer : Ultraviolet
Description : ___________ is a satellite that rotates around the earth in a low-altitude elliptical or circular pattern. A. Geosynchronous satellite B. Nonsynchronous satellite C. Prograde satellite D. Retrograde satellite
Last Answer : B. Nonsynchronous satellite
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics
Last Answer : d. Fiber optics
Description : Fiber optic cables operate at frequencies near a. 20MHz b. 200MHz c. 2GHz d. 800THz
Last Answer : d. 800THz
Description : A disadvantage of using a trap antenna. A. It will radiate harmonics B. It can only be used for single-bad operation C. It is too sharply directional at lower frequencies D. It must be neutralized
Last Answer : A. It will radiate harmonics
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
Description : How can multiple earth stations share a satellite on the same frequencies? A. Frequency reuse B. Multiplexing C. Mixing D. Frequency hopping
Last Answer : A. Frequency reuse
Description : Which of the following types of noise becomes of great importance at frequencies? A. Shot noise B. Random noise C. Impulse noise D. Transit-time noise
Last Answer : D. Transit-time noise
Description : Which of the following frequencies is normally used for distress and safety communications? A. 4209.5 kHz B. 490 kHz C. 518 kHz D. 2174.5 kHz
Last Answer : D. 2174.5 kHz
Description : What is the channel spacing for SITOR frequencies? A. 500 Hz B. 170 Hz C. 300 Hz D. 3 kHz
Last Answer : A. 500 Hz
Description : What is the channel spacing for MF-HF voice frequencies? A. 2.8 kHz B. 500 Hz C. 3.5 kHz D. 3 kHz
Last Answer : D. 3 kHz