Electronic Devices and Circuit Theory-Communications
Electronic Devices and Circuit Theory-Communications
1. An AM demodulator can be implemented with a linear multiplier followed by a ________ filter.
- low-pass
- high-pass
- band-pass
- band-stop
2. The intermediate frequency in a standard AM receiver is
- 455 Hz
- 455 kHz.
- 4.55 MHz.
- none of the above
3. Light may be propagated along a fiber-optic cable in which of the following modes?
- multimode step index
- single-mode step index
- multimode graded index
- all of the above
4. In AM, the carrier is changed by a modulating signal. What parameter of the carrier is changed?
- amplitude
- frequency
- pulse width
- phase
5. The output spectrum of a ________ modulator includes upper-side and lower-side frequencies and the carrier frequency.
- balanced
- standard amplitude
- none of the above
6. Amplitude modulation is a ________ process.
- multiplication
- division
- sum/difference
- [NIL]
7. What does VCO stand for?
- Visually-Controlled Organization
- Voltage-Controlled Oscillator
- Voltage-Centered Oscilloscope
8. A phase-locked loop (PLL) is a feedback circuit consisting of a
- phase detector.
- low-pass filter.
- VCO.
- all of the above
9. If a 1 MHz carrier is amplitude modulated with a 5 kHz audio signal, the upper-side frequency is ________ kHz.
- 1005
- 1000
- 995
- none of the above
10. The purpose of the balanced modulator is to remove the carrier frequency.
- TRUE
- FALSE