RFTop 10 Electronics Interview Questions and Answers
Advertisement
This article provides a set of electronics interview questions and answers, crafted by electronics specialists, to help you ace your electronics job interview. These questions are applicable to a wide range of electronics-related roles, including testing, design, and installation. They are also valuable as viva questions for college students.
Question 1: What is the difference between BJT and FET? Explain each.
Answer:
- BJT: Bipolar Junction Transistor
- FET: Field Effect Transistor
The key difference is that a BJT is a current-controlled device, while a FET is a voltage-controlled device.
Question 2: Explain the function of a Zener diode and one of its applications in an electronic circuit.
Answer:
A Zener diode operates in reverse bias. Its primary function is to limit any voltage exceeding its breakdown voltage. This characteristic makes it ideal for use as a voltage regulator in power supplies and various other electronic circuits.
Question 3: Explain the function of an oscillator and mention different types of oscillators.
Answer:
An oscillator serves as a source of frequency generation. It finds extensive use in frequency synthesizers, scalar signal generators, and vector signal generators.
Common types of oscillators include:
- Wein bridge oscillator
- Colpitts oscillator
- Clapp oscillator
- Crystal oscillators
Question 4: Draw the circuit of an AM receiver and an FM receiver and explain.
Answer:
An AM receiver rectifies and decodes Amplitude Modulated signals.
An FM receiver rectifies and decodes Frequency Modulated signals.
Question 5: Explain the function of a multivibrator and mention types of multivibrators?
Answer:
A multivibrator is essentially a two-stage RC-coupled amplifier.
Common types of multivibrators include:
- Astable multivibrator
- Monostable multivibrator
- Bistable multivibrator
Question 6: What is the difference between SCR, DIAC, TRIAC, UJT, and a Junction Transistor?
Answer:
- SCR: Silicon Controlled Rectifier
- DIAC: Diode for Alternating Current
- TRIAC: Triode for Alternating Current
- UJT: Unijunction Transistor
The image below depicts the symbol and structure of a TRIAC:
Question 7: Explain different logic gates and mention their truth table of operation.
Answer:
The fundamental logic gates in digital electronics are:
- AND
- OR
- EX-OR (XOR)
Other logic gates, such as NAND, NOR, EX-NOR, are derived from these basic gates. Truth tables define the output for all possible input combinations for each gate.
Question 8: Explain the internal architecture of the 8051 microcontroller? Explain timers used in microcontroller and their functions.
Answer:
The internal architecture of the 8051 microcontroller includes the following components:
- CPU
- RAM
- ROM
- UART (Universal Asynchronous Receiver/Transmitter)
- Ports
- Counters
The 8051 typically uses the following timers:
- Timer-0
- Timer-1
- Timer-2
These timers are utilized for introducing delays and for baud rate generation.
Question 9: Mention the difference between RS232 and RS485.
Answer:
Both RS232 and RS485 are serial communication interface buses.
- RS232: Primarily used for point-to-point connections.
- RS485: Designed for point-to-multipoint connections.
Question 10: Explain Op-amplifier parameters and mention a popular op-amp with its applications.
Answer:
Common parameters of an Operational Amplifier (Op-Amp) include:
- Voltage gain
- Input and output impedance
- CMRR (Common-Mode Rejection Ratio)
- Bandwidth
- Slew Rate
A popular and versatile op-amp is the 741 Op-Amp. It has a multitude of applications, including amplification, filtering, and signal conditioning.
Question 11 : Explain the difference between FIR filter and IIR filter.
Answer:
- FIR: Stands for Finite Impulse Response Filter.
- IIR: Stands for Infinite Impulse Response Filter.
These electronics interview questions and answers are highly beneficial for engineers interviewing for roles such as electronic engineer, electronics and communication engineer, design engineer, and microcontroller hardware/software engineer.
For microcontroller programming positions, proficiency in C programming is often assessed during the selection process. These questions are also valuable for students preparing for college viva examinations.
