An <ideal operational amplifier> has \b[infinite <input impedance>], so neither input draws <electric current>, and \b[zero <output impedance>], so its prescribed output <voltage> is independent of the output <electric current> within the ideal model. These are the two additional assumptions needed here.

Solution

Past exam of the physics 2 paper of the University of Oxford / 2022 / 2 / i / Solution

 Solution (source code)