Physics 9702 · AS & A Level · Characteristics of alternating currents

Characteristics of alternating currents — practice question

An ideal operational amplifier (op-amp) possesses infinite voltage gain together with infinite slew rate.
(a(i))[1]

State what voltage gain means.

(a(ii))[2]

State the meaning of infinite slew rate.

(b)[2]

Fig. 8.1 shows a non-inverting amplifier made with an ideal op-amp. The op-amp is supplied at $+9\,\text{V}/-9\,\text{V}$. The amplifier circuit has a voltage gain of $12$. Find the resistance $R$.

(c)[4]

For the circuit in Fig. 8.1, Fig. 8.2 shows how the input potential $V_{IN}$ to the amplifier changes with time $t$. On Fig. 8.3, sketch the time variation of the output potential $V_{OUT}$ from $t = 0$ to $t = t_2$.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: voltage gain = output voltage / input voltage

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