Electrical Engineering XYZ MCQs
Voltage controlled oscillators are used commonly in:
- Phase Clocked loops
- Pulse Modulators Frequency Modulators Phase Clocked loops
- Frequency Modulators
- All of these
Correct answer: 4. All of these
Explanation: Voltage-controlled oscillators (VCOs) are versatile electronic circuits commonly used in various applications across different fields. Let’s break down each option:
- Phase-Locked Loops (PLLs): VCOs are a crucial component in PLLs. In PLLs, the VCO generates an output signal whose frequency and phase are locked to the frequency and phase of an input reference signal. This locked relationship allows for frequency synthesis, clock recovery, demodulation, and various other applications.
- Pulse Modulators: VCOs can be employed in pulse modulators to generate pulses of variable frequency. By modulating the voltage input to the VCO, the frequency of the output pulses can be controlled. Pulse modulation techniques like pulse-width modulation (PWM) or pulse-frequency modulation (PFM) often utilize VCOs for this purpose.
- Frequency Modulators: Similarly, VCOs can serve as frequency modulators. By modulating the voltage input to the VCO, the frequency of the output signal can be controlled. This makes VCOs suitable for applications such as frequency modulation (FM) in communication systems or other frequency modulation techniques.
- All of these: Given the explanations above, it’s evident that VCOs are indeed commonly used in all the mentioned applications: phase-locked loops, pulse modulators, and frequency modulators. Therefore, the correct answer is “All of these.”