Technical Interviews: Excel with Ease

Block 3

Operational Amplifiers

1. What are the main attributes of an operational amplifier?
2. What gives an opamp very high input impedance?
3. What is the phenomenon of virtual earth in an opamp?
4. Does virtual earth mean that the non-inverting input of the opamp always behaves like ground potential when the inverting input is grounded?
5. Let us the take the case of an inverting amplifier with a gain of 10. If the non-inverting input of the opamp is applied to a fixed DC potential of 3 volts, what do you think will be the potential of the inverting input of the opamp?
6. Can you tell me the name of the opamp in which the non-inverting input function is derived from the inverting input function? I will give you a hint! It is named after the name of the scientist ...