Electronic Devices and Circuit Theory-Communications Questions and Answers
Understanding Electronic Devices and Circuit Theory is crucial for students of electronics and communication engineering preparing for exams like GATE, BEL, DRDO, and ISRO. This section offers comprehensive aptitude questions and answers with explanations covering diodes, transistors, amplifiers, and circuit behavior under different conditions. Solving these practice problems enhances your conceptual clarity and analytical thinking. The questions are designed to match real exam standards, with step-by-step solutions for easy understanding. Whether you’re preparing for a core electronics placement or government technical test, practicing these electronics aptitude questions with solutions PDF will give you the confidence to excel in your next exam.
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