Electronic Design MCQ Questions

A voltage follower is a specific configuration of an operational amplifier that provides a voltage gain of exactly one. This means the output voltage perfectly tracks the input voltage in both magnitude and phase without any amplification or attenuation. Consequently, if the input signal has a peak-to-peak amplitude of 0.3V, the circuit will reproduce this exact same value at the output terminals. The internal feedback loop ensures that the output adjusts dynamically to match the input, resulting in a final output of 0.3 Vpp.

The Wien Bridge Oscillator is specifically designed to generate low-frequency sinusoidal signals, typically in the audio range from 1 Hz to 100 kHz, making it ideal for a 1 kHz output. It utilizes a lead-lag RC network in its feedback path to determine the frequency, avoiding the bulky inductors required by LC oscillators like Hartley or Colpitts circuits. This topology provides excellent frequency stability and low distortion at audio frequencies, which is why it is the standard choice for generating 1 kHz oscillations in audio applications.

The Hartley oscillator is uniquely defined by its use of a tapped inductor within the LC tank circuit to provide the necessary feedback for oscillation. This single coil is split into two sections, where the tap point connects to the active device, creating a specific phase relationship that sustains the signal. Unlike other designs that rely on capacitive voltage division, this inductive coupling method is the core characteristic of the Hartley topology. Consequently, identifying the tapped coil feature directly points to the Hartley circuit as the correct classification. This configuration allows for flexible frequency tuning by adjusting the inductance values or the tap position.