A 50 microvolt wave at sensitivity 5 microvolts/mm produces a deflection of:

To determine the deflection produced by a 50 microvolt wave at a sensitivity of 5 microvolts per millimeter, it is important to apply the principle that sensitivity indicates how much deflection on the recording device corresponds to each unit of voltage.

Given the sensitivity of 5 microvolts per millimeter, it means that every increase of 5 microvolts will move the tracing on the graph by 1 millimeter. To find out how many millimeters correspond to a 50 microvolt wave, you divide the total voltage by the sensitivity:

Total deflection (in mm) = Total voltage (in microvolts) / Sensitivity (in microvolts/mm)

Using the values from the question:

Total deflection = 50 microvolts / 5 microvolts/mm = 10 mm

This calculation shows that a 50 microvolt wave at a sensitivity of 5 microvolts/mm will produce a deflection of 10 mm on the recording device. Thus, the correct answer is 10 mm, meaning that if the answer chosen was 10 mm, the student has correctly understood the relationship between voltage and sensitivity in this context.