G1 and G2 in a simple monitoring setup represent which of the following?

G1 and G2 in a simple monitoring setup represent which of the following?

• A. The first signal input and the ground lead, respectively
• B. The ground lead and the first signal input, respectively
• C. The first signal input and the second signal input, respectively
• D. The ground lead and the exploring electrode, respectively

Answer: (A)

In a simple two-lead recording, the two leads form a single channel where one lead supplies the actual signal and the other provides a stable reference. The first lead is the signal input—the electrode that carries the physiological signal into the amplifier. The second lead serves as the ground/reference, helping to stabilize the signal and reduce noise. That’s why G1 corresponds to the first signal input and G2 to the ground lead. Swapping these or treating both as signal inputs wouldn’t match how a two-lead setup is wired, and terms like an exploring electrode aren’t part of this labeling.

In a simple two-lead recording, the two leads form a single channel where one lead supplies the actual signal and the other provides a stable reference. The first lead is the signal input—the electrode that carries the physiological signal into the amplifier. The second lead serves as the ground/reference, helping to stabilize the signal and reduce noise. That’s why G1 corresponds to the first signal input and G2 to the ground lead. Swapping these or treating both as signal inputs wouldn’t match how a two-lead setup is wired, and terms like an exploring electrode aren’t part of this labeling.