test.2.txt (2178B)
1 6)a)i) in book 2 6)a)ii) To ensure that there is no loading effect caused by the low output impedance of the microphone 3 6)b)i) in book 4 6)b)ii) in book 5 6 7)a)i) in book 7 7)a)ii) because random noise will slightly adjust the height of the peeks, which in PPM doesn't change the encoded data, while in PAM the height of the peaks does effect the encoded data (because the amplitute stores the signal) 8 7)b)i) in book 9 7)b)ii) in book 10 7)b)iii) a number is taken in parralel, and is put into a shift register. Each bit is shifted down through the registers, in the graphs, through to register D, where it is then sent as an individual pulse down the serial wire, this process is repeated by shifting each register down. 11 12 8)a) in book 13 8)b)i) in book 14 8)b)ii) in book 15 8)b)iii) This is because all the current in the system must flow through the 10 Ohm resistor to get to the other components. 16 8)c)i) in book 17 8)c)ii) in book 18 8)c)iii) It wouldn't recive the correct volatage or current values, as the ripple voltage is too high, and thus the zenner wont always be working with the desired power 19 8)d)i) this would remove (most of) the ripple and allow the user to set the voltage to a fixed value 20 8)d)i) in book 21 22 9)a) S1 and S2 are both triggers for the system, if either of them are pressed the thyristor will turn on, thus making the alarm set off. There are 2 switches to allow for multiple alarm points (perhaps one on each door). S3 will turn of the alarm 23 9)b) in book 24 9)c) in book 25 9)d)i) S3 is pressed 26 9)d)ii) at the start, before Y dips to 0V, the alarm is turned on and the thyristor is conducting, this is because there is 0V over the thyristor, which means all 12V must be over the alarm, turning it on. When S3 is pressed (Y dips to 0V) the alarm will turn off because the thyristor has been reset. It will now have 12V over it until the alarm is triggered again either by S1 or S2 27 28 10)a)i) this is interference, an unwanted signal being applied over the top of the desired signal, an example of this is a strong magnet, as when moved over a wire, they can change the voltages, thus applying a noise to the signal 29 10)a)ii) in book 30 10)b)i) in book 31 10)b)ii) in book 32 10)b)iii) in book 33