Which term describes a circuit that consists of four sections connected in series to form a closed loop?

• A. Amplifier
• B. Bridge circuit
• C. Attenuator
• D. Amplification

Answer: (B)

A bridge circuit is defined by four arms forming a closed loop, with opposite arms acting as two potential dividers and a detector (often a galvanometer) bridging the middle. This four-section loop arrangement is the hallmark of a bridge circuit, such as the Wheatstone bridge, which lets you compare or balance impedances very precisely. Amplifier and amplification refer to devices or actions that increase signal, while an attenuator reduces it; they describe functions or components, not the four-arm loop topology. So the term that fits a circuit built from four sections connected in series to make a closed loop is a bridge circuit.