RSMTC Foundations Practice Exam

Linearity means the output follows a straight-line relationship with the input over the range you care about. In sensors and ADCs, this shows up as a transfer that can be described by y = gain × x + offset, so the output changes at a constant rate as the input changes. If you double the input, the output should double (after accounting for gain and offset) within the specified range. The line can have an offset and a slope, but the key is a constant slope—no bending or curvature within that range. Outside the operating range, nonlinearities may creep in and the relationship stops being perfectly linear. This is why the correct idea is that the output is proportional to input within a specified range. It isn’t required to be exactly equal to the input (that would be a unit gain with zero offset), it isn’t inverse proportional, and it isn’t independent of input.