(a)[2]
State two effects that negative feedback has on the gain of an amplifier using an operational amplifier (op-amp).
(b(i))[2]
Fig. 9.1 shows an incomplete circuit diagram of a non-inverting amplifier with an ideal op-amp. Finish the circuit diagram in Fig. 9.1. Add labels for the input and the output.
(b(ii))[2]
Calculate the resistance of resistor $R$ required for the non-inverting amplifier to have a voltage gain of $15$.
(c)[2]
On Fig. 9.2, draw a graph to show how the output potential $V_{OUT}$ varies with input potential $V_{IN}$. Consider input potentials from $0$ to $+1.0\,\text{V}$.
(d)[2]
The output of the amplifier circuit in Fig. 9.1 may be linked to a relay. State and explain one purpose of a relay.