Interview Questions in Electronics (2024)

25 Interview Questions in Electronics (With example)

Electronics is a branch of engineering that deals with the study and application of electrical circuits, devices, and systems. It involves the control of the flow of electrons or other electrically charged particles to achieve a particular functional result.

What is the difference between Electronics and Electrical?

Electronics deals with devices that operate on DC with a voltage range of -48vDC to +48vDC. Electrical devices, on the other hand, work on line voltage (e.g., 120vAC, 240vAC). While electronic devices include computers, radios, and TVs, electrical devices include incandescent lights, heaters, and refrigerators.

What is communication?

Communication is the process of transferring a signal from a transmitter through a medium to a receiver. It involves transmitting messages from one place to another.

Different types of communications? Explain.

There are two main types of communication: analog and digital. Analog communication involves the modulation of continuous signals, while digital communication involves the transmission of discrete signals represented by binary digits (1s and 0s).

What is latch-up?

Latch-up is a failure mechanism in which a parasitic thyristor is inadvertently created within a circuit, causing a high amount of current to continuously flow through it once it is accidentally triggered. This can lead to permanent destruction of the device.

What is a diode?

In electronics, a diode is a two-terminal device that allows current to flow in one direction only. It has two active electrodes, an anode, and a cathode, between which the current flows.

What is a transistor?

A transistor is a semiconductor device commonly used to amplify or switch electronic signals. It is the fundamental building block of computers and all other modern electronic devices.

What is sampling?

Sampling is the process of obtaining a set of discrete samples from a continuous signal. It involves measuring the value of the signal at regular intervals.

State sampling theorem.

The sampling theorem states that to accurately reconstruct a continuous signal from its samples, the sampling rate must be equal to or greater than twice the highest frequency component of the signal.

What are the advantages of resistors?

  • Resistors are very small in size.
  • They are easy to carry from one place to another.
  • Resistors are cost-effective.

What is the principle of microwave?

Microwave technology operates in the frequency spectrum from 1 GHz to 30 GHz. It is used for communication because lower frequency bands are congested. Microwaves propagate in spacewave and are suitable for point-to-point communication.

What is the cut-off frequency?

The cut-off frequency is the frequency at which the response of a system is -3dB with respect to the maximum response.

What is passband?

The passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.

What is stop band?

A stopband is a band of frequencies, between specified limits, in which a circuit, such as a filter or a telephone circuit, does not allow signals to pass through.

Define Power Rating?

The power rating of a diode is defined as the maximum value of power that can be dissipated without failure. It is calculated as the product of the forward biased voltage and current.

What is a rheostat?

A rheostat is a type of variable resistor used to control the flow of electric current by manually increasing or decreasing its resistance.

What is demodulation?

Demodulation is the process of removing the modulation from an analog signal to retrieve the original baseband signal.

Explain radio environment in a building.

  • Building penetration: It depends on the material and architecture used in construction.
  • Building Height Effect: Signal strength is higher at the top floor, with a floor gain height of about 2.7 dB/floor.
  • Building Floor Reception: Signal isolation between floors is about 20 dB, and propagation loss due to interior walls is about 20 dB.

What is a resistor?

A resistor is a two-terminal electronic component that opposes the flow of electric current. It produces a voltage drop between its terminals in proportion to the current passing through it, according to Ohm’s law (V = IR).

What is an inductor?

An inductor is a passive electrical device used in electrical circuits for its property of inductance. It can take many forms and is used to store energy in the form of a magnetic field.

What is a conductor?

A conductor is a substance, body, or device that readily conducts heat, electricity, sound, etc. Copper is an example of a good electrical conductor.

What is a semiconductor?

A semiconductor is a solid material that has electrical conductivity between that of a conductor and an insulator. It can vary its conductivity over a wide range, either permanently or dynamically.

Name the modulation techniques.

  • For Analog modulation: AM, SSB, FM, PM, and SM.
  • For Digital modulation: OOK, FSK, ASK, Psk, QAM, MSK, CPM, PPM, TCM, and OFDM.

Explain AM and FM.

  • AM (Amplitude Modulation): The amplitude of the carrier signal is varied in accordance with the information-bearing signal.
  • FM (Frequency Modulation): The frequency of the carrier signal is varied in accordance with the information-bearing signal.

Explain RF.

RF (Radio Frequency) is a frequency or rate of oscillation within the range of about 3 Hz to 300 GHz. It corresponds to the frequency of alternating current electrical signals used to produce and detect radio waves.

What is modulation? And where is it utilized?

Modulation is the process of varying some characteristic of a periodic wave with an external signal. It is utilized in radio communication to superimpose an information-bearing signal onto a carrier signal, allowing it to be transmitted over long distances.

What is feedback?

Feedback is a process whereby some proportion of the output signal of a system is passed (fed back) to the input. It is used to control the dynamic behavior of the system.

What are the parts of a Network Management System (NMS)?

  • OMC (Operation and Maintenance Center)
  • NMC (Network Management Center)
  • OSS (Operation and Support System)

How many satellites are required to cover the earth?

Three satellites are required to cover the entire earth, positioned at 120 degrees to each other. The lifespan of a satellite is approximately 15 years.

What are GPRS services?

GPRS services are categorized as either Point-to-Point (PTP) or Point-to-Multipoint (PTM). They include services like internet access, multimedia messaging, and email.

What is a repeater?

A repeater is an electronic device that receives a signal and retransmits it at a higher level or power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation.

What is an Amplifier?

An amplifier is an electronic circuit or device used to boost or amplify the power, current, or voltage of an applied signal.

Example for negative feedback and positive feedback?

An example of negative feedback is an amplifier, while an example of positive feedback is an oscillator.

What is an Oscillator?

An oscillator is a circuit that creates a waveform output directly from a direct current input. There are two main types: harmonic and relaxation.

What is an Integrated Circuit (IC)?

An integrated circuit (IC), also called a microchip, is an electronic circuit etched onto a small piece of silicon. It is made up of a complex network of transistors, resistors, and capacitors.

What is handover and what are its types?

Handover, in mobile communication, refers to the process of transferring a call from one network cell to another without breaking the call. There are two types:

  • Hard Handoff
  • Soft Handoff

What is crosstalk?

Crosstalk is a form of interference caused by signals in nearby conductors. It can lead to unwanted signals being picked up by adjacent circuits or devices.

What is op-amp?

An operational amplifier, or op-amp, is a DC-coupled high-gain electronic voltage amplifier with differential inputs and, usually, a single output. It is commonly used in analog electronic circuits.

Explain Bluetooth.

Bluetooth is a wireless technology standard used for exchanging data over short distances. It operates in the 2.4 GHz frequency band and provides a range of up to 10 meters. Bluetooth offers transfer speeds of around 720 Kbps.

What is feedback?

Feedback is a process whereby some proportion of the output signal of a system is passed (fed back) to the input. It is used to control the dynamic behavior of the system.


  • CDMA (Code Division Multiple Access): A channel access method used by various radio communication technologies.
  • TDMA (Time Division Multiple Access): Divides access by time.
  • FDMA (Frequency Division Multiple Access): Divides access by frequency.

Explain different types of feedback.

There are three types of feedback:

  • Negative Feedback: Reduces output and stabilizes the system.
  • Positive Feedback: Increases output and can lead to oscillation.
  • Bipolar Feedback: Can either increase or decrease output.

What are the main divisions of the power system?

The main divisions of the power system are:

  • Generating system
  • Transmission system
  • Distribution system

What is an Instrumentation Amplifier (IA) and what are its advantages?

An instrumentation amplifier is a differential op-amp circuit providing high input impedances with ease of gain adjustment by varying a single resistor.

Explain the concept of frequency re-use.

Frequency re-use is a technique used in cellular communication systems to maximize the use of available radio frequency spectrum. It involves dividing a geographical area into smaller cells and reusing the same set of frequencies in different cells, ensuring that adjacent cells use different frequencies to avoid interference

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