Electronics Engineering (ELEX) Board Practice Exam

Which of the following circuits is commonly used to create a feedback loop in amplifiers?

1. Voltage divider

2. Current source

3. Negative feedback loop

4. Resistive load

The correct answer is: Negative feedback loop

Feedback loops are essential components in amplifier circuits that help improve stability, bandwidth, and linearity. A negative feedback loop specifically refers to a technique where a portion of the output signal is fed back to the input out of phase with the input signal. This process reduces the gain of the amplifier but enhances its stability and reduces distortion. Using negative feedback allows for better control over the amplifier's characteristics, such as increasing linearity and reducing the effects of variations in temperature and component tolerances. It enables the amplifier to operate more predictably and effectively within its intended performance specifications. The other options, while having their own roles in circuits, do not specifically pertain to creating a feedback loop in amplifiers. A voltage divider typically sets input voltage levels, a current source provides a constant current, and a resistive load is a component that consumes power from the amplifier but does not implement feedback. Therefore, the use of a negative feedback loop is central to managing and optimizing amplifier performance.