The output of a microphone is processed using a non-inverting amplifier. The amplifier incorporates an operational amplifier (op-amp). (a) State, by reference to the input and output signals, the function of a non-inverting amplifier.

1. (a)State, by reference to the input and output signals, the function of a non-inverting amplifier.[2]
2. (b)The circuit for the microphone and amplifier is shown in Fig. 7.1. [Figure 7.1] The output potential difference VOUT is 2.6 V when the potential at point P is 84 mV. Determine: (i) the gain of the amplifier circuit[1]
3. (b)(ii)the resistance of resistor R.[2]
4. (c)For the circuit of Fig. 7.1: (i) suggest a suitable device to connect to the output such that the shape of the waveform of the sound received by the microphone may be examined[1]
5. (c)(ii)state and explain the effect on the output potential difference VOUT of increasing the resistance of resistor R.[2]

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