A battery-resistor analogy for further insights on measurement   uncertainties
  We use analogies to give introductory laboratory students intuition about measurement uncertainties. Using a battery-resistor circuit we discuss uncertainty concepts and derive expressions for uncertainty of the mean and sums of uncertainties. Finally, we draw attention to the fact that the interpretation of standard deviation as uncertainty depends on the statistical distribution of the data, while the interpretation of uncertainty of the mean is largely insensitive to such distribution, especially for large samples. If the resistor in the battery-resistor circuit is a resistive loudspeaker, the uncertainty or noise is literally the acoustic power of the sound produced by such noise. In the sound analogy the statistical distribution of the noise is related to its timbre. 
Gabriel L. A. de Sousa, George C. Cardoso
physics.ed-ph