80+ Hardware Engineer Interview Questions and Answers

The number of ways to arrange sets of coloured balls in a line.

• The number of ways to arrange the red balls is the factorial of the number of red balls.

• The number of ways to arrange the blue balls is the factorial of the number of blue balls.

• The number of ways to arrange the green balls is the factorial of the number of green balls.

• To find the total number of arrangements, multiply the number of arrangements for each set.

Overlap-add method of convolution is implemented by dividing the input signal into overlapping segments and convolving each segment with a filter.

• Divide the input signal into overlapping segments

• Apply the filter to each segment

• Add the convolved segments together to get the output signal

• The length of each segment should be greater than or equal to the length of the filter

• The overlap between adjacent segments should be greater than or equal to the length of the filter minus one

The bit-rate for quantization of a band-limited signal can be obtained by considering the Nyquist-Shannon sampling theorem.

• The Nyquist-Shannon sampling theorem states that in order to accurately represent a band-limited signal, the sampling rate must be at least twice the highest frequency component of the signal.

• The bit-rate for quantization is determined by the number of bits used to represent each sample. It is typically calculated as the product of the sampling rate and t...read more

The in-phase and quadrature components of a real pass-band signal can be obtained using a complex mixer.

• A complex mixer is used to convert the real pass-band signal to a complex baseband signal.

• The in-phase component is obtained by multiplying the pass-band signal with a local oscillator signal in-phase with the carrier frequency.

• The quadrature component is obtained by multiplying the pass-band signal with a local oscillator signal 90 degrees out of phase with the carrier fre...read more

Nyquist sampling frequency for unevenly distributed band-limited signal.

• Determine the highest frequency component in the signal

• Use Nyquist theorem to calculate the minimum sampling frequency

• Sampling frequency should be at least twice the highest frequency component

To determine maximum frequency of operation from a complex diagram

• Identify the critical path in the diagram

• Calculate the propagation delay of each component in the path

• Use the formula fmax = 1 / (2 * propagation delay) to determine maximum frequency

• Consider any setup or hold time requirements for flip-flops or other components

• Ensure that the frequency is within the specifications of the components used

Demodulating a QAM signal involves separating the amplitude and phase components to recover the original data.

• QAM signals combine amplitude and phase modulation

• Demodulation involves separating the amplitude and phase components

• Techniques like coherent demodulation and quadrature demodulation are used

• Coherent demodulation uses a local oscillator to recover the phase component

• Quadrature demodulation separates the in-phase and quadrature components

DC-DC converters are used to convert DC voltage levels. Flyback converters are a type of DC-DC converter.

• DC-DC converters are used to convert DC voltage levels

• Types of DC-DC converters include buck, boost, buck-boost, and flyback converters

• Flyback converters use a transformer to store energy and transfer it to the output

• Flyback converters are commonly used in low-power applications

• Flyback converters can provide isolation between input and output

I designed a system that integrates hardware components to perform specific functions efficiently.

• Researched and selected appropriate hardware components based on project requirements.

• Designed circuit layouts and schematics to ensure proper functionality.

• Implemented testing procedures to validate system performance.

• Optimized system for cost-effectiveness and efficiency.

• Regularly updated system to incorporate new technologies and improvements.

To turn on an LED using PNP and NPN transistors, connect the LED to the collector of the NPN transistor and the emitter of the PNP transistor.

• Connect the anode of the LED to the collector of the NPN transistor and the cathode to the emitter of the PNP transistor.

• Apply a positive voltage to the base of the NPN transistor to turn it on, allowing current to flow through the LED.

• Apply a negative voltage to the base of the PNP transistor to turn it on, completing the circuit and t...read more

Yes, I am willing to work rotational shifts as required for the job.

• I am flexible and adaptable to different work schedules.

• I understand the importance of meeting project deadlines and will adjust my schedule accordingly.

• I have previous experience working in rotational shifts at my previous job.

• I am committed to my work and will ensure that my performance is not affected by the shift changes.

Overlap-add is implemented by dividing the input signal into overlapping segments, applying a window function, and adding the segments together.

• Overlap-add is a method used in digital signal processing to efficiently convolve long signals with finite impulse response (FIR) filters.

• The input signal is divided into overlapping segments, typically with a length equal to the filter length.

• A window function, such as the Hamming window, is applied to each segment to reduce spectral...read more

Data can be shared between PCs using various methods such as network sharing, cloud storage, USB drives, and email.

• Network sharing: Using a local network to transfer files between PCs.

• Cloud storage: Uploading files to a cloud service like Google Drive or Dropbox and downloading them on another PC.

• USB drives: Copying files onto a USB drive and physically transferring it to another PC.

• Email: Attaching files to an email and sending them to another PC.

The command for checking system connectivity is 'ping'

• The 'ping' command is used to test the reachability of a host on an IP network

• It sends ICMP echo request packets to the target host and waits for a response

• The response time and packet loss can be used to determine the connectivity status

Designing a digital system for detecting start bit in UART communication

• The start bit is the first bit in a UART transmission and is always a logic low

• The system should sample the incoming data at a rate higher than the baud rate to accurately detect the start bit

• A shift register can be used to store the incoming data and detect the start bit

• The system should also check for framing errors and parity errors

Hardware requirements for Windows 10 installation include processor, RAM, storage, and graphics card.

• Processor: 1 gigahertz (GHz) or faster processor or SoC

• RAM: 1 gigabyte (GB) for 32-bit or 2 GB for 64-bit

• Storage: 16 GB for 32-bit OS or 20 GB for 64-bit OS

• Graphics card: DirectX 9 or later with WDDM 1.0 driver

Yes, I have hardware knowledge.

• I have a strong understanding of computer hardware components such as CPUs, GPUs, RAM, and motherboards.

• I am familiar with hardware design principles and have experience in designing and prototyping electronic circuits.

• I have knowledge of various hardware interfaces and protocols like USB, HDMI, PCIe, and I2C.

• I am proficient in using hardware testing and debugging tools like oscilloscopes, multimeters, and logic analyzers.

• I have worked on hardwa...read more

Call by value passes a copy of the variable, call by reference passes the actual variable, and call by pointer passes the memory address of the variable.

• Call by value: Changes made to the parameter inside the function do not affect the original variable. Example: int x = 10; func(x);

• Call by reference: Changes made to the parameter inside the function affect the original variable. Example: void func(int &x) { x = 20; }

• Call by pointer: Passes the memory address of the variable....read more

Yes, I have experience in Emi EMC analysis.

• I have conducted Emi EMC analysis on various hardware designs.

• I am familiar with the relevant standards and regulations.

• I have used tools such as SPICE and MATLAB to perform simulations.

• I have worked with shielding and grounding techniques to reduce interference.

• I have collaborated with cross-functional teams to ensure compliance.

• For example, I conducted Emi EMC analysis on a medical device to ensure it met FDA regulations.

I have had a successful career as a Hardware Engineer, specializing in designing and developing computer hardware components.

• I have a Bachelor's degree in Electrical Engineering.

• I have worked for 5 years at ABC Electronics, where I designed and tested circuit boards for computer systems.

• I have experience in FPGA programming and have successfully implemented complex algorithms on hardware.

• I have collaborated with cross-functional teams to ensure the seamless integration of har...read more

Design a traffic control using Moore state machine

• Identify the states of the traffic control system

• Design the state transition diagram

• Implement the state machine using digital electronics

• Test the system with different traffic scenarios

Opamp stands for operational amplifier, a type of electronic amplifier with high gain and differential inputs.

• Opamp stands for operational amplifier

• It has high gain and differential inputs

• Different types include inverting, non-inverting, differential, instrumentation, etc.

D flip flop is a digital circuit that stores a single bit of data and is used in sequential logic circuits.

• D flip flop has a data input (D), a clock input (CLK), a set input (S), and a reset input (R).

• When the clock input is high, the value of D is transferred to the output Q.

• When the set input is high, the output Q is set to high.

• When the reset input is high, the output Q is reset to low.

• D flip flop is used in applications like shift registers, counters, and memory units.

SQL is a programming language used for managing and manipulating relational databases.

• SQL stands for Structured Query Language

• Basic concepts include SELECT (retrieve data), INSERT (add data), UPDATE (modify data), DELETE (remove data)

• SQL uses commands like SELECT, INSERT, UPDATE, DELETE, JOIN, WHERE, GROUP BY, ORDER BY, etc.

• SQL is used to interact with databases like MySQL, PostgreSQL, Oracle, SQL Server, etc.

The number of components in a desktop can vary depending on the specific model and configuration.

• Components can include the CPU, GPU, RAM, motherboard, storage devices, power supply, cooling system, and peripherals.

• Examples of components in a desktop: Intel Core i7 processor, NVIDIA GeForce RTX 3080 graphics card, 16GB DDR4 RAM, ASUS ROG Strix Z590-E motherboard, 1TB SSD, 750W power supply, liquid cooling system, keyboard, mouse, monitor.

I have 5 years of experience in hardware engineering.

• I have worked on designing and testing circuit boards.

• I have experience in troubleshooting hardware issues.

• I have worked with various hardware components such as microcontrollers, sensors, and actuators.

• I have also collaborated with software engineers to integrate hardware and software systems.

I have used protocols such as I2C, SPI, UART, and CAN in my projects.

• I2C (Inter-Integrated Circuit) for communication between microcontrollers and sensors

• SPI (Serial Peripheral Interface) for high-speed communication between devices

• UART (Universal Asynchronous Receiver-Transmitter) for serial communication between devices

• CAN (Controller Area Network) for communication in automotive applications

FPGAs are Field-Programmable Gate Arrays used in hardware design. They can be categorized as SRAM-based, Flash-based, or Antifuse-based.

• SRAM-based FPGAs are volatile and require reprogramming every time they power up. Examples include Xilinx Virtex series.

• Flash-based FPGAs are non-volatile and retain their configuration even when powered off. Examples include Actel ProASIC3 series.

• Antifuse-based FPGAs are OTP (One-Time Programmable) and cannot be reprogrammed once configured....read more

Flip flops and latches are sequential logic circuits used in digital electronics to store and transfer data.

• Flip flops are clocked circuits that store one bit of data, while latches are level-sensitive circuits that store data as long as the enable signal is active.

• Flip flops are edge-triggered, meaning they change state on a clock edge, while latches are level-triggered, changing state as long as the enable signal is active.

• Examples of flip flops include D flip flop, JK flip...read more

DNS stands for Domain Name System, which translates domain names to IP addresses.

• DNS is like a phone book for the internet, translating human-readable domain names (like google.com) to IP addresses (like 172.217.3.206).

• DNS servers store a database of domain names and their corresponding IP addresses.

• DNS helps users access websites and other online services by resolving domain names to IP addresses in the background.

An operating system is a software that manages computer hardware and software resources and provides common services for computer programs.

• It acts as an interface between the user and the computer hardware.

• It manages memory, processes, and input/output devices.

• Examples include Windows, macOS, Linux, and Android.

• It provides a platform for other software to run on.

• It ensures security and stability of the system.

I have a stable financial situation.

• I have a steady income from my current job as a hardware engineer.

• I have been able to save and invest money over the years.

• I have no outstanding debts or financial obligations.

• I have a good credit score and financial track record.

• I have a diversified portfolio of investments.

• I have a budget and financial plan in place to ensure stability.

• I have emergency savings to cover unexpected expenses.

A Database Management System (DBMS) is a software that manages and organizes data in databases.

• DBMS helps in creating, updating, and managing databases.

• It provides tools for data retrieval, storage, and manipulation.

• Examples of DBMS include MySQL, Oracle, and Microsoft SQL Server.

Bode plot for CS amplifier shows gain and phase response with frequency.

• Bode plot consists of two plots - one for gain (in dB) and one for phase shift (in degrees) vs frequency.

• The gain plot typically shows a high-pass filter response with a peak at the resonant frequency.

• The phase plot shows a 180 degree phase shift at the resonant frequency.

• Bode plots are useful for analyzing frequency response of amplifiers and filters.

Regulators are selected based on input/output voltage requirements, current capacity, efficiency, package size, and cost.

• Consider input/output voltage requirements

• Evaluate current capacity needed

• Look at efficiency ratings

• Take into account package size and form factor

• Compare costs of different regulators

• Examples: Linear regulators, switching regulators, voltage regulators

To troubleshoot a slow PC, check for malware, free up disk space, disable startup programs, update software, and upgrade hardware if needed.

• Run a malware scan to check for any malicious software slowing down the system

• Free up disk space by deleting unnecessary files and programs

• Disable unnecessary startup programs that may be running in the background

• Update software, drivers, and operating system to ensure optimal performance

• Consider upgrading hardware components like RAM or ...read more

The work in desktop involves designing, testing, and troubleshooting computer hardware components.

• Designing and developing computer hardware components such as motherboards, processors, and memory modules

• Testing hardware components to ensure they meet performance and quality standards

• Troubleshooting hardware issues and providing solutions to improve performance

• Collaborating with software engineers to ensure hardware compatibility and optimization

Physical address is the location of a specific memory location in a computer's memory.

• Physical address is a unique identifier for a specific memory location in a computer's memory

• It is used by the hardware to access and retrieve data stored in that memory location

• Physical addresses are typically represented in hexadecimal format

A proxy server acts as an intermediary between clients and servers, forwarding requests and responses.

• Proxy servers can be used for caching, filtering, and improving security.

• They can also be used to access restricted content by masking the user's IP address.

• Examples of proxy servers include Squid, Apache mod_proxy, and Nginx.

Component engineering involves selecting, designing, and integrating electronic components into a system.

• Component engineering involves selecting appropriate electronic components for a system

• It also involves designing custom components if necessary

• Integrating the selected components into the overall system design is a key aspect of component engineering

Processor cores are individual processing units within a CPU that can execute instructions independently.

• Processor cores allow for parallel processing, increasing overall performance.

• More cores generally lead to better multitasking capabilities.

• Examples of processors with multiple cores include Intel Core i7-9700K (8 cores) and AMD Ryzen 9 3900X (12 cores).

DHCP stands for Dynamic Host Configuration Protocol, which is a network management protocol used to assign IP addresses to devices on a network.

• DHCP automatically assigns IP addresses to devices on a network

• It helps in reducing the manual configuration of IP addresses

• DHCP servers lease IP addresses to devices for a specific period of time

• DHCP also provides other network configuration information to devices, such as subnet mask and default gateway

Opamp amplifiers are used in various applications such as audio amplification, instrumentation, and signal conditioning.

• Opamp amplifiers are commonly used in audio amplification circuits to increase the amplitude of audio signals.

• In instrumentation applications, opamp amplifiers are used to amplify small signals from sensors or transducers.

• Opamp amplifiers are also used in signal conditioning circuits to filter, rectify, or modify signals before they are processed.

• Other appli...read more

ELCB stands for Earth Leakage Circuit Breaker. It is used to protect against electric shock and electrical fires.

• ELCB is a safety device that detects and cuts off the power supply when there is a leakage of current to the earth.

• It is installed in the electrical distribution board and monitors the current flowing through the live and neutral wires.

• If there is a difference in the current flow, it means that some current is leaking to the earth and the ELCB trips, cutting off th...read more

Blue windows come from a feature called Blue Screen of Death (BSOD) in Windows operating systems.

• Blue windows appear when a system error occurs in Windows operating systems, commonly known as Blue Screen of Death (BSOD).

• BSOD is designed to provide information about the error that caused the system crash.

• The blue color is used to make the error message stand out and grab the user's attention.

• Blue windows are often associated with system crashes and hardware failures in Windows...read more

Use a 4:1 mux to create a 3 input XOR gate.

• Connect two of the inputs to the select lines of the mux.

• Connect the third input to one of the data inputs of the mux.

• Connect the other data input of the mux to the output of an XOR gate between the first two inputs.

• Use the output of the mux as the output of the 3 input XOR gate.

A router is a networking device that forwards data packets between computer networks.

• Routers connect multiple devices to the internet or other networks.

• They use IP addresses to route data packets to their destination.

• Routers can be wired or wireless, and can be used in homes, businesses, and data centers.

• Examples of popular router brands include Cisco, Netgear, and TP-Link.