(a(i))[1]
State what this circuit is called.
(a(ii))[3]
Explain why point P is described as a virtual earth.
(b)
Fig. 11.1 is changed, as shown in Fig. 11.2.
(b(i))[3]
Fig. 11.1 is changed, as shown in Fig. 11.2. The voltmeter has infinite resistance and its full-scale deflection is $1.0\text{ V}$. The input potential to the circuit is $V_{IN}$. The switch position can be altered so that different resistance values are present in the circuit. The input potential $V_{IN}$ and the switch setting are varied. For each switch position, the voltmeter reading is $1.0\text{ V}$. Complete Fig. 11.3 for the switch positions shown.
(b(ii))[1]
Using your answers in (i), suggest a use for the circuit of Fig. 11.2.