Electronics Design

Here we are going to list down the frequently most asked Electronics Design Interview Questions for professionals. The questions are created and submitted by professionals to help you to ace the job interviews.

Q.1 What are MOFETs?
MOFETs are voltage controlled devices with high input impedance.
Q.2 What is the main advantage of precision rectifiers over conventional rectifiers?
In conventional rectifiers the input voltage should go above the cut-off voltage of the diode before rectification takes place but all voltages can be rectified in precision.
Q.3 Why are EPROM/ROM/PROM called a programmable logic device?
EPROM/ROM/PROM are called a programmable logic device because we can implement Boolean expressions by storing its truth table in the ROM.
Q.4 What is the main difference between PLA and PAL logic?
Flexibility is available before AND as well OR in the case of PLA while it is available only before AND in the case of PAL
Q.5 What is the main advantage in a JK flip-flop over an SR flip-flop?
When both inputs of each flip-flop are '1', in the case of SR, the out put is a forbidden case but this has been modified to a toggle case in the JK flip-flop
Q.6 What is the main factor which makes a MOSFET likely to break-down during normal handling?
The main factor which makes a MOSFET likely to break-down during normal handling is its very low gate capacitance and high input resistance.
Q.7 What is the main reason why electrons can tunnel through a P-N junction?
The main reason why electrons can tunnel through a P-N junction is that depletion layer is very thin.
Q.8 Why is a clock added to the SR flip-flop to convert it into a clocked SR flip-flop?
The flip-flop operation can be synchronised to a high level of the clock.
Q.9 Explain diode?
A diode is a gadget that has two incurable states. Most diodes are chosen for their unidirectional present quality, as they have two living electrodes between which the gesture of attention can flow.
Q.10 Define sampling.
Sampling is the process of acquiring a sample location from a permanent purpose of time x (t).
Q.11 What is the microwave's working principle?
Microwave is a term that refers to an extremely tiny wave. Microwave incidence spectrums are commonly assumed to extend from 1GHz to 30GHz. The main reason we need to employ microwave frequency for communication is that the lower incidence band is overcrowded, and the need for point-to-point communication continues to grow. Microwave broadcasting takes place in space wave in v.
Q.12 What do you mean by passband?
The passband refers to the range of frequencies or wavelengths that can pass through a filter without attenuation.
Q.13 Define Power Rating.
When V f is the onward biassed voltage and I f is the limiting forward current, the power rating of a diode is defined as the maximum value of power that may be degenerate without failure. Pd= V f x I f
Q.14 Explain demodulation.
Demodulation is the process of removing the intonation from an analogue signal in order to recover the unique baseband signal. Because the handset system receives a modulated signal with specific parameters and must twist it to base-band, demodulation is required.
Q.15 What do you mean by the resistor?
A resistor is a two-terminal electrical component that opposes an electric current by causing a voltage drop between its terminals equal to the current, in accordance with Ohm's law: IR = V.
Q.16 Explain the term inductor.
An inductor is a passive electrical device that works in electrical circuits because of its inductance properties. An inductor can come in a variety of shapes and sizes.
Q.17 What is modulation techniques?
For Analog modulation--AM, FM, PM, SSB and SM Digital modulation--OOK, PPM, FSK, ASK, CPM, Psk, QAM, MSK, TCM, OFDM
Q.18 Explain what is RF?
Radiofrequency refers to oscillation regularity or speed in the range of 3 Hz to 300 GHz. This frequency range relates to the occurrence of irregular current electrical signals, which are utilised to generate and detect radio waves. Because most of this variation exceeds the shaking rate that most mechanical systems can withstand, RF is usually used to refer to electrical circuit oscillations.
Q.19 What are the applications of AM and FM?
AM is used for video indications, for example, TV. Ranges from 535 to 1705 kHz. FM is utilized for audio signals, for example Radio. Ranges from 88 to 108 MHz
Q.20 What exactly do you mean when you say 'base station'?
The base station is a radio receiver that serves as the hub of a local wireless network and can also act as a gateway between a wired and wireless network.
Q.21 Define repeater.
A repeater is an electrical gadget that receives a signal and retransmits it at a higher level or on the other side of an obstacle so that the signal can wrap around larger distances without becoming distorted.
Q.22 What do you mean by Amplifier?
A functional signal's power, voltage, or presence is increased using an electronic gadget.
Q.23 Define Oscillator
An oscillator is a track that converts a shortest current input into a signal form output. Vocal and relaxation oscillators are the two most common forms of oscillator. The waveforms of harmonic oscillators are horizontally curved, whereas waveforms of repose oscillators are jagged.
Q.24 What is crosstalk?
Signals in close conductors generate crosstalk, which is a type of interference. The most common example is overhearing a phone conversation. Crosstalk can also occur in radios, televisions, networking equipment, and other electronic devices.
Q.25 Define Bluetooth.
Bluetooth is designed to be a character area network (CAN) for mobile devices that need to communicate with each other on a regular basis. It is omnidirectional, as opposed to infrared, which has a row of sight limitations. Bluetooth uses the 2.4 GHz frequency band and has a range of 10 metres. It can transfer data at a rate of roughly 720 Kbps.
Q.26 Explain the main division of power system.
The main divisions are: Transmission system Generating system Distribution system
Q.27 What is the concept of frequency re-use?
Each cell has its own transceiver, and the entire physical region is divided into hexagonal shape geometrical areas called cells. Each BTS possessed a unique band of incidence or channel. Each BTS aerial is designed to cover the cell region in which it is installed with the appropriate incidence without interfering with another sale signal.
Q.28 Define semiconductor.
A semiconductor is a hard substance with electrical conductivity that falls somewhere between that of a conductor and that of an insulator, and it can vary in that range either permanently or dynamically.
Q.29 What are active and passive components?
Active components, such as diodes, transistors, and thyristors, are electrical components that require an external source to complete their processes. Unreceptive components are ones that do not require the use of an external source to function. Resistor, capacitor, and inductor are examples of passive components.
Q.30 Define SCR
A silicon controlled rectifier is a unidirectional semiconductor machine with three terminals: anode, cathode, and gate, unlike a diode. The entrance input can be used to turn on and off the SCR.
Q.31 What is a Capacitor?
A capacitor is a two-terminal electrical component that holds charge as potential energy. Capacitance is the attribute or ability of a capacitor to store charge, and it is measured in Farad. The equation q = CV can be used to calculate the stored charge q.
Q.32 Define Inductor.
An inductor is an electronic component that inhibits the flow of electrical current through it. When current passes through it, it stores energy in the form of a magnetic field. V = L (di/dt) can be used to compute the voltage drop across an inductor.
Q.33 Explain what is Practical & Ideal Voltage Source?
A practical voltage source is a voltage source with some internal resistance. There is a voltage loss as a result of this resistance. With an increase in current, the supply voltage of the practical voltage source drops. When a voltage source's internal resistance reaches zero, it is considered to be an ideal voltage source. And as the current increases, the voltage does not decrease.
Q.34 What is Norton theorem?
In a linear circuit, any combination of batteries and resistances is comparable to and may be represented by an ideal current source and a parallel resistor.
Q.35 What is Thevenin theorem?
A signal voltage source and a resistor in series can represent any combination of batteries and resistance in a linear circuit.
Q.36 Define Transistor.
A transistor is a semiconductor device with three terminals. It can be used to switch or magnify an electrical signal.
Q.37 What is the function of the transistor as a switch?
A transistor's three useful operating zones are the saturation region, cutoff region, and active region. The transistor functions as an amplifier in the active region. The transistor works as a closed switch in the saturation region. The transistor operates as an open switch in the cutoff zone. As a result, in order to use a transistor as a switch, it must be operated in the saturation and cutoff regions.
Q.38 What is meant by Clipper and Clamper?
A clipper is a circuit that cuts off voltage when it exceeds or falls below a given threshold. The positive clipper removes a portion of the signal's positive half, whereas the negative clipper removes the negative half. A clamper is a circuit that adds voltage to a specified peak voltage from the signal's positive or negative side. To obtain the set peak voltage, a clamper moves the entire signal up and down.
Q.39 Define SCR.
The silicon controlled rectifier, also known as a thyristor, is a unidirectional semiconductor device with three terminals: anode, cathode, and gate. The gate input can be used to turn on and off the SCR.
Q.40 What exactly is a diode?
A diode is a semiconductor device that has two terminals: anode and cathode. The forward bias of a diode allows current to flow in just one direction.
Q.41 What is the difference between a Silicon and a Germanium Diode, and why is the former preferred?
A silicon diode has a voltage drop of 0.7v, while a germanium diode has a voltage drop of 0.3v. Silicon crystals are more heat resistant than germanium crystals. The voltage rating of a silicon diode is higher than that of a germanium diode. Silicon diodes are preferred over germanium diodes because silicon is more abundant.
Q.42 What is the main difference between BJT and FET?
Bipolar junction transistor is abbreviated as BJT, and Field Effect Transistor is abbreviated as FET. BJTs are bipolar, meaning they have a flow of both minority and majority charge carriers, whereas FETs are unipolar, meaning they only have a flow of majority charge carriers. The input current (base current) is used to operate BJTs, whereas the input voltage is used to control FETs (Gate voltage). FETs have a substantially higher input impedance than BJTs. Emitter, base, and collector are the three terminals of a BJT, whereas drain, gate, and source are the three terminals of a FET.
Q.43 Define Transformer.
A transformer is a static electrical device that employs electromagnetic induction to transmit electrical energy from one circuit to another without using any physical connections. The input voltage and current are increased or decreased using a transformer.
Q.44 Explain Oscillator.
An oscillator is an electrical circuit that converts a DC source into a periodic AC signal. There is no input to an oscillator. The oscillator's output can be sinusoidal, square, or triangular wave.
Q.45 What is Baseband Signal?
A baseband signal is a signal that has a much lower frequency (up to 10 kHz). Voice (300Hz to 3.5 kHz), audio (20 Hz to 20 kHz), and video signals are examples of baseband signals (0Hz to 4.5 MHz). The baseband signal can't be sent through the antenna directly. Copper cable or fibre optics, for example, are used to transmit them.
Q.46 What is the difference between a Bandpass and a Passband Signal?
The term "Passband" or "BandPass" refers to a transmission with much higher frequencies (more than 100 kHz). There are no frequencies lower than 100 kHz in a bandpass signal. The bandpass signal can be transmitted directly through the antenna.
Q.47 Define Modulation.
Modulation is the process by which one of the carrier signal's distinctive parameters (amplitude, frequency, or phase) changes linearly with respect to the message signal's amplitude.
Q.48 Why do we need Modulation?
Modulation is the process of converting a baseband signal into a passband signal that can be used for long-distance communication via an antenna. Since the size of the antenna is determined by the frequency of the transmitting signal, modulation allows us to employ a small antenna. We can assign various frequencies to separate signals via modulation, allowing us to convey several messages over the same media without interfering with each other.
Q.49 Define Demodulation.
The process of retrieving information or a message signal from a received or modulated signal is known as demodulation.
Q.50 What are the types of Modulation?
Analog and digital modulation are the two primary types of modulation.
Q.51 What is the difference between Analog and Digital signal
Digital signals have discrete time and discrete amplitude, whereas analogue signals have continuous time and continuous amplitude.
Q.52 Define Sampling.
A procedure of transforming a continuous time signal into a discrete time signal, but not a digital signal, is known as sampling.
Q.53 What is the Nyquist Criteria for Sampling?
If the analogue signal's maximum frequency is fmax, the Nyquist requirements suggest that the sampling rate for this signal should be 2fmax or higher.
Q.54 Explain Aliasing.
Aliasing is a sampling-related signal phenomenon. When a signal is sampled at a rate lower than the needed rate, it becomes indistinguishable from other signals, and when the signal is reconstructed, it does not resemble the original signal. Aliasing is the term for this phenomena.
Q.55 What is a Filter?
A filter is an electrical circuit that removes frequency components from a signal that are specific or undesired.
Q.56 What is the Cutoff Frequency?
The cutoff frequency is the frequency response of a filter where the pass band and stop band meet. Depending on the type of filter, frequency components below or above the cutoff frequency are rejected or passed.
Q.57 Define Notch filter.
The notch filter is a band stop filter that has a very small stop band.
Q.58 Explain Logic Gate.
The Boolean function is implemented by a digital logic gate, which is an electronic device. A logical operation is performed on one or more binary numbers using the boolean function.
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