Polarography and amperometry differ in that polarography measures current at which condition?

• A. Increasing voltage
• B. Constant voltage
• C. Both at increasing voltage
• D. Both at constant voltage

Answer: (A)

In polarography the electrode potential is swept upward (increasing voltage) while the current is recorded continuously. This creates a current-versus-voltage plot (polarogram) that shows how the current responds as the driving force increases, often rising and then leveling off at the diffusion-limited current. Amperometry, on the other hand, fixes the potential and watches how the current changes with time after applying that constant potential. So polarography measures current under increasing voltage, which is why that option is the correct description.