How does your brain know which direction a sound comes from ?

Your brain is able to do this by comparing tiny differences in the way that sounds affect each ear. ... Signals from the ear travel along the auditory nerve to the brainstem, where each individual cell responds to a specific time difference and direction.

Explanation:

It's because of your ears.

Explanation:

For resistances in parallel we know that the overall resistance will be smaller in the value than any individual resistance. so, in this case we are concerned about = ⁺

where Rs is the series resistor and Rp is the parallel resistor.

so, R = 0.9M, roughly.

So, as the infernal resistance is very high as compared to the resistance conntected in parallel that is 100 Ω is not be used.