During the wet lab recordings, because nerve APs are such small signals, to view them you had to Blank 1 Question 11 the signals being recorded. This will also increase the size of the electrical Blank 2 Question 11 and so it was necessary to apply filtering to remove unwanted signals. You could get rid of the mains power supply noise by using a Blank 3 Question 11 filter, which removed all Blank 4 Question 11 frequency signals like those that make up the electrical supply in Australia