Operational amplifiers abbreviated as op-amps are named so because in the beginning these were used primarily to perform mathematical
operations such as addition, subtraction, integration, and differentiation. In old days, op-amps were made using vacuum tubes. Modern Op-Amps are integrated circuits that operate on low dc supply voltages. Present days Op-amps are reliable and inexpensive devices. Given below are the most important basic Operational Amplified MCQ Questions with brief explanatory answers and solutions.
Contents
The ideal OP-AMP has the following characteristics
The ideal OP-AMP has the following characteristics
- Ri = ∞, AV = ∞, RO = 0
- Ri = ∞, AV = ∞, RO = ∞
- Ri = 0, AV = ∞, RO = 0
- Ri = 0, AV = 0, RO = ∞
Correct answer: 1. Ri = ∞, AV = ∞, RO = 0
In the common mode Op-amp
In the common mode Op-amp:
- An identical signal appears on both the inputs
- Both inputs are grounded
- The output signal are in-phase
- The outputs are connected together
Correct answer: 1. An identical signal appears on both the inputs
In case of an ideal OP-amp
In case of an ideal OP-amp:
- The current from output terminal is zero
- The current into the input terminals is zero
- The differential voltage across the input terminals is zero
- The output resistance is zero
Correct answer: 1. The current from output terminal is zero
The common mode gain of Op-amp is
The common mode gain of Op-amp is:
- Always unity
- Very high
- Very low
- Unpredictable
Correct answer: 3. Very low
The tail current in a differential amplifier equals
The tail current in a differential amplifier equals:
- Collector current divided by current gain
- Collector voltage divided by collector resistance
- Difference between two emitter currents
- Sum of two emitter currents
Correct answer: 1. Sum of two emitter currents