In this article, we are going to learn about the Analog Electronics Interview Questions And Answers in a very detailed manner. This question we have covered is most important for interviews.
Analog Electronics Interview Questions
Que.1: What do you mean by operational Amplifier?
Answer: An operational amplifier is a direct-coupled, high-gain amplifier used for some mathematical operations such as addition, subtraction, multiplication, integration, differentiation, logarithmic operations, etc.
Que.2: List the ideal characteristics of an op-amp.
- infinite voltage gain
- Infinite input resistance
- Zero output resistance
- Zero output offset voltage
- Zero input offset voltage
- Infinite bandwidth
- Infinite CMRR ( Common mode rejection ratio)
- infinite slew rate
Que.3: What are the main features of IC-741?
- No external frequency compensation required
- Short circuit protection
- offset null capability
- large common-mode and differential voltage range
- low power consumption
- No latch-up problem
Que.4: What is input offset voltage in op-amp?
Answer: Due to the non-linearity of the components in the circuits, there will be some output voltage available at op-amp even if the input voltage is not applied. So to null the output voltage at zero minimum input voltage is applied at the input of op-amp which is called input offset voltage. In short, the Minimum input voltage required to null the output voltage at zero is called input offset voltage.
Que.5: what do you mean by CMRR (Common mode rejection ratio)?
Answer: The significance of CMRR is the capability of the op-amp to reject the common-mode inputs available at the inverting and non-inverting terminal. Noise is the signal which is common at both the terminals of the op-amp. So in short CMRR is high means the op-amp capability is high to reject the noise signal so that it will not affect the output signal. CMRR is the ratio of the differential voltage gain to the common-mode voltage gain.
Que.6: Discuss the SVRR?
Answer: The full form of SVRR is the supply voltage rejection ratio. The change in an op-amp offset voltage caused by a variation in supply voltage is called the Supply voltage rejection ratio (SVRR).
Que.7: What is the Slew rate of an op-amp?
Answer: The slew rate is the maximum rate of change of output voltage per unit of time. The unit of slew rate is v/μs.
Que.8: Explain the effects of hysteresis.
Answer: It improves noise immunity. It reduces the response time. It reduces false triggering. When hysteresis increases then sensitivity reduces.
Que.9: Explain the timer IC-555.
Answer: IC-555 is a timer IC that is used in a stable multivibrator, square wave generator, triangular wave generator, pulse modulator, and pulse detector circuits.
Que.10: Explain IC.
Answer: An IC ( Integrated Circuit) is a miniature, low-cost electronic circuit consisting of active and passive components fabricated together on a single crystal of silicon. The active components are transistors, diodes, etc, and the passive components are resistors and capacitors.
Que.11: What are the advantages of ICs over discrete circuits?
- Minimization & hence increase equipment density
- Cost reduction due to batch processing
- Increase system reliability
- Improved functional performance
- matched devices
- Increased operating speed
- Reduction in power consumption
Que.12: Process of fabricating ICs using planner technology.
- Silicon wafer (substrate) preparation
- Epitaxial growth
- Ion implantation
- Isolation technique
- Assembly processing & Packaging
Que.13: List some linear applications of the op-amp.
Answer: Adder, Subtractor, Voltage to current converter, Current to voltage converter, Instrumentation amplifier, Power amplifier, etc.
Que.14: List some non-linear applications of the op-amp.
Answer: Rectifier, Peak detector, Clipper, Clamper, Sample and Hold Circuit, Log amplifier, Anti-log amplifier, Multiplier, etc.
Que.15: What is Filter? Why filter is used?
Answer: A filter circuit is a device that converts the pulsating output of a rectifier into a steady-state dc level. It is essential to reduce the ripples from the pulsating dc supply available from rectifier circuits to the minimum to protect the load from damage. This is achieved by using a filter or smoothing circuit which removes the ac components and allows only dc components to reach the load. The filter circuit is always placed between the rectifier and the load.
Que.16: What are the commonly used types of filter circuits?
Answer: 1. Series Inductor Filter, 2. Shunt Capacitor Filter, 3. Choke Input Filter, 4. Capacitor input or Pie Filter
Que.17: What are the drawbacks of the series inductor and shunt capacitor filter?
Answer: A simple shunt capacitor filter reduces the ripple voltage but increases the diode current. The diode may get damaged due to the large current and at the same time, it causes greater heating of the supply transformer resulting in reduced efficiency. In an induction filter, the ripple factor increases with the increase in load resistance while in a capacitor filter, it varies inversely with the load. From the economical point of view, neither series inductor nor shunt capacitor types filter is suitable.
Que.18: What is Clipper?
Answer: In electronics, a clipper is a device designed to prevent the output of a circuit from exceeding a predetermined voltage level without distorting the remaining part of applied waveforms. Series clippers are employed as noise limiters in FM transmitters by clipping excessive noise peaks above a specified level.
Que.19: Application of Clippers.
Answer: It is used in television sets and FM receivers. It is also used for amplifiers and different types of opamps through which we can do some mathematical operations.
Que.20 What are oscillators?
Answer: Oscillators produce a waveform of desired amplitude and frequency. They can take input from the output itself. For a complete oscillator circuit, we require a feedback device, amplifier, and feedback factor. Oscillators designed to produce a high-power AC output from a DC supply are usually called inverters.
Que.21 Why do we use the level shifter stage in op-amp?
Answer: The unbalanced output of the differential amplifier has DC in it which if passed to the output, may change the operating point or biasing conditions and result in distortions in output.
Que.22 Why do we use a compensation capacitor?
Answer: It is used to improve the stability of op-amp but it reduces the slew rate of op-amp because of the charging-discharging of the capacitor.
Que.23 Drawback of IC 741 op-amp.
Answer: Small slew rate which limits its application in high-frequency circuits.
Que.24 What is an instrumentation amplifier?
Answer: It is a circuit that converts changes in a physical process into amplifier voltages. It has a bridge network to detect changes in physical parameters followed by a voltage buffer and the differential amplifier.
Que. 25 Why op-amp is more used as an integrator but not as a differentiator?
Answer: In differentiator circuits, the high-frequency gain becomes too high so the circuit becomes unstable, and at high frequency, it provides amplification to noise frequency and noise also increased.
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