(a(i))[1]
State what infinite bandwidth means.
(a(ii))[1]
State what zero output impedance means.
(b(i))[2]
Fig. 7.1 shows a non-inverting amplifier circuit using an ideal op-amp. The light-emitting diode (LED) gives out light when the potential difference across it is at least $2.0\,\text{V}$. The current in the LED must not be more than $20\,\text{mA}$. Calculate the gain of the amplifier circuit.
(b(ii))[1]
Determine the value of $V_{IN}$ when $V_{OUT}$ is $+2.0\,\text{V}$.
(b(iii))[1]
State the highest value of the output potential $V_{OUT}$.
(b(iv))[2]
When the op-amp is saturated, the potential difference across the LED is $2.2\,\text{V}$. Calculate the smallest resistance of resistor $R$ needed so that the current in the LED does not exceed $20\,\text{mA}$.