IoT interview questions

Last updated on Nov 20, 2023

The Internet of Things (IoT) is a network of physical objects or individuals referred to as "things" that are equipped with software, electronics, networks, and sensors to capture and share data. The aim of the Internet of Things is to expand internet access from mainstream devices such as laptops, phones, and tablets to relatively basic devices such as toasters.

In this article, you can go through the set of IoT interview questions most frequently asked in the interview panel. This will help you crack the interview as the topmost industry experts curate these at HKR training.

Most Frequently Asked IOT Interview Questions

Let us have a quick review of the IoT interview questions.

IoT Basic Interview Questions

What are the fundamental components of IoT?

Ans: The four fundamental components of an IoT system are:

  • Sensors/Devices: Sensors or devices are essential components for gathering real-time data from the environment. Almost all of this information may be complicated in any manner. It may be a basic temperature control sensor or a video feed.
  • Connectivity: The information gathered is submitted to a cloud infrastructure. The sensors should be linked to the cloud through a variety of communication channels. Mobile or satellite networks, Bluetooth, WI-FI, WAN, and other networking systems are examples of these mediums.
  • Data Processing: Once the data is collected and transferred to the cloud, the software product processes the information. This method can be as easy as testing the temperature or readings from equipment such as air conditioners or heaters. However, it can also be incredibly challenging, such as detecting objects using computer vision on video.
  • User Interface: The data must be open to the end-user in any manner, which can be done by setting off alarms on their phones or giving them updates by email or text message. The consumer can sometimes need an app that actively controls their IoT device.

What is Pulse Width Modulation?

Ans. PWM refers to Pulse Width Modulation and is an analog signal that differs when the signal stays high. The user can alter the time proportion as the signal can be high or low.

What are the challenges of IoT?

Ans: Important challenges of IoT are:

  • Insufficient testing and updating.
  • Concern regarding data security and privacy.
  • Software complexity.
  • Data volumes and interpretation.
  • Integration with AI and automation.
  • Devices require a constant power supply which is difficult.
  • Interaction and short-range communication.

What are mostly used IoT protocols?

Ans: The mostly used IoT protocols are:

  • XMPP.
  • AMQP.
  • Very Simple Control Protocol (VSCP).
  • Data Distribution Service (DDS).
  • MQTT protocol.
  • WiFi.
  • Simple Text Oriented Messaging Protocol(STOMP).
  • Zigbee.

What is WSN?

Ans: WSN stands for Wireless Sensor Network in its full form. It's a network of notes generated to map and analyze the application's physical parameters.

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What is Zigbee?

Ans. Zigbee is similar to Bluetooth, used within a complex system for low power function, high security, and robustness.

What is Z-Wave?

Ans: Z-Wave is an Internet of Things (IoT) application that utilizes low-power RF communication. It's built for things like lamp controllers and controls that are used in home automation.

What is MQTT?

Ans: MQTT stands for Message Queue Telemetry Transport Protocol in its full form. It's a communications protocol for monitoring devices in the Internet of Things.

What are the various types of antennas designed for IoT devices?

Ans: Various types of antennas designed for IoT devices are:

  • Chip Antenna.
  • PCB Antenna.
  • Wire Antenna.
  • Proprietary Antenna.
  • Whip Antenna.

. What are the types of IoT?

Ans: The following are the different types of IoT:

1) Commercial IoT - This IoT system is mainly used in the industries like transport, healthcare, etc. 

2) Military Things (IoMT) - These types of IoT applications are mostly used in the military area, such as surveillance bots, etc.

3) Consumer IoT - This type of IoT is generally used in everyday work, such as home appliances, light fixtures, etc.

4) Infrastructure IoT - This IoT system helps establish connectivity in smart cities, such as sensor management. 

5) Industrial IoT - It mainly helps in industrial fields such as manufacturing, energy, smart agriculture, etc.

. What is Asset Tracking?

Ans: The method of keeping track of physical properties and information is referred to as asset tracking or asset management.

. What is the basic difference between the IoT network and Wireless Sensor Network?

Ans: Things attached to the wireless network and collecting data or tracking the environment are part of the Wireless Sensor Network. The Internet of Things (IoT) is made up of.

  • WSN.
  • Internet.
  • Cloud Storage.
  • Web or mobile application.

. What is Shodan?

Ans: Shodan is an IoT monitoring application that will help you find out which of your computers are online. It helps you to keep track of all of the machines that have direct Internet connectivity.

. Define Arduino.

Ans: Arduino is a free electronics application that contains both hardware and software that is simple to use. It has a microcontroller that can read sensor data and programmatically control the motors.

. What are IoT test approaches?

Ans: IoT test approaches are: 

1) Usability.

2) IoT Security.

3) Connectivity.

4) Performance.

5) Compatibility Testing.

6) Pilot Testing .

7) Regulatory Testing, and 

8) Upgrade testing.

. What Python libraries used in Raspberry Pi to control GPIO pins?

Ans: RPi.GPIO is the python libraries used in Raspberry Pi to control GPIO pins.

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. What is PWM?

Ans: Pulse Width Modulation (PWM) is an acronym for pulse width modulation. In an analog way, pulse width modulation helps one to adjust the length of time the signal is high. We can adjust the proportion of time the signal is high relative to when it is low over a constant time interval, even if the signal can either be high (usually 5V) or low (ground) at any given time.

IoT Intermediate Interview Questions

. What is the basic difference between the IoT network and Wireless Sensor Network?

Ans: Items attached to the wireless network and collecting data or tracking the environment are part of the Wireless Sensor Network. The Internet of Things (IoT) is made up of:

  • WSN.
  • Internet.
  • Cloud Storage.
  • web or mobile application.

. Explain the types of testing in IoT?

Ans: The following are a list of IoT testing types:

  • Usability Testing: Users use a wide variety of devices of varying shapes and forms. Also, one user's experience differs from another's. As a consequence, in IoT testing, it's vital to determine the system's usability.
  • Compatibility Testing: The Internet of Things (IoT) framework will connect a wide variety of devices. The software and hardware specifications of these tools differ. As a consequence, the number of potential combinations is immense. As a consequence, it's crucial to verify the IoT system's compatibility.
  • Reliability and Scalability Testing: Building an IoT test system that includes a simulation of sensors using virtualization software and technology requires reliability and scalability.
  • Data Integrity Testing: Since IoT research necessitates a vast volume of data and its implementation, it's essential to verify data integrity.
  • Security testing: Many users of the IoT community have access to a vast volume of data. As a result, it is essential to authenticate users and enforce data privacy controls as part of security testing.
  • Performance Testing: Performance testing is crucial for developing and implementing a strategic approach to IoT testing.

. Mention suitable databases for IoT.

Ans: Suitable databases for IoT are:

  • influx DB.
  • Apache Cassandra.
  • RethinkDB.
  • MongoDB.
  • Sqlite.

. What is the importance of the Internet of Everything?

Ans: Internet of Everything is important because:

  • People, processes, things, and data are all pulled together to make network links meaningful and vital.
  • It turns data into practices, allowing companies to build new skills and opportunities.

Related Article: Future Scope of IoT

. Define IoT Contiki

Ans: Internet of Things (IoT) Contiki is a software program developed especially for small Internet-connected devices. It is used in accordance with process power bandwidth, power, and memory constraints. Contiki assists in program management, resource management, process management, communication, and memory management.

. What is the default operating system of Raspberry Pi, May I use any other operating systems?

Ans: Yeah, we can use Windows and any Linux operating system built for Arm-based devices, but Raspbian is the Raspberry Pi's default operating system.

. How to run Raspberry pi in headless mode?

Ans: SSH can be used to run the Raspberry Pi in headless mode. The most recent operating system has an inbuilt VNC server, which can be used to take a remote desktop on the Raspberry Pi.

. What are the popular software IDEs are using in IoT?

Ans: Each prototype system family has its production IDE, such as the Arduino IDE, Keil IDE, GCC compilers, and so on

What popular hardware prototypes are used in IOT?

Ans: The following hardware prototypes are used within IoT: Raspberry Pi, Arduino, and ARM Cortex Family.

. What are the available models in Raspberry Pi?

Ans:  The modes in Raspberry are as follows:

  • Raspberry Pi 1 model B.
  • Raspberry Pi 1 model A.
  • Raspberry Pi 1 model B+.
  • Raspberry Pi 1model A+.
  • Raspberry Pi Zero.
  • Raspberry Pi 2.
  • Raspberry Pi 3 model B.
  • Raspberry Pi Zero W.

. What is Bluetooth Low Energy (BLE) Protocol for an Internet of Things (IoT)?

Ans: Nokia first implemented this protocol in 2006 as wibree. Because of the unique Bluetooth, this protocol is also known as Bluetooth Smart. It provides the same spectrum coverage with a substantial reduction in intensity intake. It has a similar bandwidth to Zigbee, which uses the same narrow spacing. Low electricity latency and reduced complexity allow it more suited for use in low-cost microcontrollers.

. State the differences between Arduino and Raspberry pi.

Ans: The difference between Arduino and Raspberry pi is:


  • Arduino is an open, programmable USB microcontroller.
  • Raspberry pi is a credit card size computer.

Raspberry pi:

  • It can execute one program at a time.
  • Users can run more than one program at a time.

. What impacts will the Internet of Things (IoT) have on the Transportation Sector?

Ans: Transportation infrastructure is becoming more and more interconnected. New automobiles are equipped with features such as global positioning systems (GPS) and in-vehicle entertainment, and advanced driver assistance systems (adas), which use sensors inside the vehicle to assist the driver with tasks such as parking and emergency braking.

. What is the programming language supported by MongoDB?

Ans: The following are the list of programming languages supported by MongoDB.

  • Actionscript info.
  • C.
  • C#.
  • C++.
  • Clojure info.
  • ColdFusion info.
  • D info.
  • Dart info.
  • Delphi info.
  • Erlang.
  • Go info.
  • Groovy info.
  • Haskell.
  • Java.
  • JavaScript.
  • Lisp info.
  • Lua info.
  • MatLab info.
  • Perl.
  • PHP.
  • PowerShell info.
  • Prolog info.
  • Python.
  • R info.
  • Ruby.
  • Scala.
  • Smalltalk.

. What are the most used sensors types in IoT?


  • Temperature sensors.
  • Proximity sensor.
  • Pressure sensor.
  • Gas sensor.
  • Smoke sensor.
  • IR sensors.
  • Motion detection sensors.

. What are the hardware communication interfaces present in the Arduino board?

Ans: It has several communication protocols like I2C, SPI, Serial, PWM and etc.

. Can NodeMCU act as a web server?

Yeah, using the Arduino library ESP8266WebServer. This is an ESP8266 catalogue. For other NodeMCU boards, related libraries are also available.

IoT Advanced Interview Questions

. Explain how you insert bulk data in MongoDB, and can write the query for that?



var huge= db.iotCollection.initializeUnorderedBulkOp();

huge.insert({location:”India”, count:456,  polls:456});

huge.insert({location:”Russia:, count:567, polls:567});

huge.insert({location:”China”, count:789,  polls:789});

huge.insert({location:”USA”, count:123, polls:123});


. What is Bluegiga APX4 protocol for an Internet of Things?

Ans: Due to their compliance with coexistence protocols, Bluegiga and wireless can be used together without interfering. The bluegiga apx4 is based on a 450mhz arm9 processor and supports both Bluetooth and Wi-Fi.

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. What are the economic impacts of the increased application of IoT?

Ans: IoT has been seen to have a positive effect on multiple industries' economic standards.IoTs can significantly decrease labor and energy costs by promoting effective resource utilization and reducing response time and human interventions. This, in essence, will help big companies improve their supply chains, making for lower-cost commodity delivery. This not only helps companies make more money, but it's also a perfect way to boost the current production infrastructure. Overall, IoT scalability is excellent, and as a result, IoT implementations save money in the long run.

. How does IoT influence the development of smart cities?

Ans: IoT devices' intuitive features, coupled with improved network interaction, allow IoT to facilitate infrastructure planning flexibility, transparency, and performance. The Internet of Things also enable energy-efficient initiatives to take off. Overall, because of the various benefits that IoT offers, the government should work to construct smart cities all over the world.

Intelligent energy grids, automated waste management systems, smart houses, enhanced protection systems, improved traffic control mechanisms, advanced security features, water-saving mechanisms, and many more are all possible with the Internet of Things. IoT has allowed public utilities and urban planning to be highly intuitive due to the two-pronged blessings of artificial intelligence and creativity. Smart homes and smart cities have resulted as a result of these innovations.

. What are the top five Machine-to-Machine (M2M) applications in the world?


  1. The biggest seems to be asset tracking and monitoring in some form or another (stolen automobiles, fleets, construction systems, wood pellets, tank level tracking, and many others.).
  2. Insurance telematics is enormous because it allows insurance companies to reduce risk and force higher/more appealing pricing.
  3. Utilities/automatic meter reading/clever grids – In the intervening period, there has been a lot of regulation, and financial support put into this. Because the requirements and business case are driven in so many various ways, there are many countrywide solutions.
  4. Consumer demand drives the automotive industry, which is also very broad.
  5. mHealth is still present, although it is not as large as it should be.

. What is the difference between a wireless sensor network (WSN) and the Internet of Things(IoT) network?


WSN: IoT packages are built based on the Wi-Fi sensor culture. WSN is a network of programmed motes to look at, analyze, or track physical parameters of utility.

e.g., Motes put in agricultural land track temperature, humidity, and likely soil moisture. They capture data, which is then analyzed to assess crop yields, consistency, and quantity.

IoT: The internet of things (IoT) is a network of physical objects that can be handled and tracked through the internet. Today, just as with winning, you'll come across the monitoring of physical criteria in its implementation. However, the preferred consequences are a bit different. M2M is at the core of IoT; it's far more than merely applying the information to everyday devices.

e.g., The system attached to your thermostat measures the ambient temperature and changes it to the most suitable environment for you.

. How might Internet Address (IPv6) affect the development and implementation of the Internet of Things?


The technological boundaries of the most commonly adopted variant of the network protocol (IP) are barriers to IoT advancement. IP is a set of rules that computers use to transmit and retrieve data over the internet, and it requires a unique address that any connected device or object should be able to communicate with. Model four (ipv4) is probably the most commonly used. It has a potential of around four billion addresses and is approaching saturation, with few new addresses available in many areas.

Version 6 (ipv6) provides for a substantial rise in the number of IP addresses available. The maximum number of specific addresses permitted by IPv4 is 4.2 billion, which is inadequate to include even one address for each of the 7.3 billion people on the planet. According to an evaluation, IPv6 would support over 1038 addresses or more than a thousand billion trillion addresses per person.

. What impacts will the Internet of Things (IoT) have on the Health Care Sector?

Ans: The Internet of Things (IoT) has various uses in the healthcare sector, including fitness monitoring and treatment and telemedicine and telehealth. Lengthy health care and training is also offered by using a medical age and the internet. Medical devices, which may be wearable or non-wearable, implantable, injectable, or ingestible, can continuously track a patient's vital signs, medical conditions, or other health and wellness indicators.

. What is IoT Thingworx?

Ans: Thingworx may be a platform for rapidly developing and launching sensible, connected devices. Its advanced IoT development tools assist with property, analysis, production, and other facets of the IoT development process.

. What are the dangers and difficulties that we ought to know about with regards to the Internet of Everything?

Ans: The dangers and difficulties that everybody ought to know about with regards to the Internet of Everything are:

  • Security.
  • System blockage.
  • Power utilization at the pinnacles.

. What is the application of IoT in Law enforcement?

Ans: The Internet of Things enhances law enforcement and surveillance, as well as the legal system. The technology increases transparency, distributes relevant information, and prevents unwanted human interference.

Remote monitoring, logged footage of violations and electronic ticketing can also help make effective solutions to issues by using technologies in the workplace. For example, you can replace the light in-person reviews of suspicious activities with remote observation, logged footage of violations, and electronic ticketing. It also eliminates misconduct by eliminating human management and opinion in the case of a few breaches.

. What is IoT GE-PREDIX?

Ans: GE (General Electric) Predix could be a software system platform for information assortment from industrial instruments. It offers a cloud-based PaaS (platform as a service) that enables industrial-grade analytics for optimising operations and controlling performance. It uses a prevalent method to link data, individuals, and instrumentation.

. Should the customers be worried about security and protection issues considering the measure of information Internet of Things (IoT) gathers?

Ans: Many people are worried about the possibility of sensitive information falling into the wrong hands due to the various measurements of data collected by smart home gadgets, wearable devices, and wearables. The increased number of passages often poses a security danger.

The Federal Trade Commission has expressed its worries and advised companies to play it safe to protect their consumers. On the other hand, the FTC lacks the experience to approve IoT device guidance, so it's unknown how many companies can take its recommendations seriously.

For example, Apple demands that businesses producing products for its HomeKit platform provide end-to-end encryption, authentication, and security. The organization also stated that it does not obtain any customer information relevant to HomeKit embellishments.

. What might be the effect of the Internet of Things hands on market, do you see any conceivable activity cuts?

Ans: To be especially obtuse about this, we will be faced with work cuts under which machines will take care of a portion of the positions that require continuity and precision. On the plus side, people can learn new skills to command machines and build their own space. This has become the rule of nature; we have everything to help us lose weight, and then we have another problem to deal with in a few months or days. As a consequence, I see this as an ideological approach to coping with our daily problems.

. What are the distinctive parts where the Internet of Things can really enhance the present procedures?

Ans: Any handle where profitability, precision, or process enhancement are needed can be linked to the Internet of Things process.With the aid of creativity and cutting-edge technologies, this can be done for a fraction of the actual working rate.

Network of items may be related or have already begun adding their advantages to the corresponding grades, which we can likely see more of in the future:

  1. Agriculture.
  2. Manufacturing.
  3. Healthcare.
  4. Energy.
  5. Transportation.
  6. Security.
  7. Data improvement.

. What impacts will the Internet of Things (IoT) have on the Energy Sector?

Ans: IoT may affect all facets of production and delivery, for example, by making oil wellheads and pipelines easier to track. As IoT modules are incorporated into electrical grid components, the resulting infrastructure is called the "smart grid."This implementation of IoT helps utilities help control the flow of electricity and increase grid operations' potency.

. What impacts will the Internet of Things (IoT) have on the Agriculture Sector?

Ans: The agricultural industry should take advantage of the Internet of Things through precision agriculture to increase productivity and potency while decreasing costs and reducing environmental effects. For farming operations, it requires a comprehensive review of extensive, usually time-based details on temperature, soil and air quality, installation, pest populations, crop maturity, and other factors such as machinery and labor costs and availability. Field sensors track soil moisture and beam balance, and they may use them in combination with position technology to fine-tune irrigation and fertilization.

. What is meant by

Ans. "Thingful" is a search engine for the Internet of Things that uses millions of public IoT data resources. It also enables secure interoperability among the different IoT objects through the internet. It uses these resources to provide a geographical index of real-time data from linked devices across the globe. Using it, the managers of IoT can quickly locate and analyze the patterns, anomalies, and trends to resolve various issues.

. What is meant by GPIO?

Ans. GPIO refers to General Purpose Input/Output and is a helpful programmable pin. It helps to control the input or output signals programmatically. Moreover, GPIO is a common interface to link other electronic devices or systems with the microcontrollers.

. Define the Network's importance in IoT?

Ans. The network is essential to IoT and offers an intelligent system that builds the most robust infrastructure. Also, it provides higher scalability to connect and coordinate devices with other channels through the internet.

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. What is meant by the Internet of Things Gateway?

Ans. IoT Gateways can connect with different IoT devices, equipment, and sensors to the cloud-based platform along with data processing. The gateway is a central hub for different IoT devices and connects them to the cloud. In this way, it converts the communication of the devices and helps in data analysis to create valuable insights.

. Explain the various IoT communication models?

Ans. IoT is all about connecting various devices through the internet to share meaningful data. Most IoT devices connect with other devices through various communication models. These communication models show the actual process of communication and its working strategy. There are different communication models available in IoT:-

  • Request Response Model
  • Push-Pull Model
  • Publisher-Subscriber Model
  • Exclusive Pair Model

. Distinguish between IoT and IIOT?

Ans. Let us know the key points of differences between IoT and IIOT.

IoT - IoT refers to the Internet of Things that connects devices and sensors through the internet. It is primarily helpful for automating home appliances, devices, sensors, etc., and it has a human-centric service model. IoT supports many human-oriented apps, and the communication transmits through wireless devices. Moreover, it serves medium to high data quality. 

IIOT- It (IIOT) refers to the Industrial Internet of Things. Its (IIOT) service model is machine-centric. The model is generally helpful in industrial areas. The model supports industry-level applications. Moreover, the quality of data it serves is high to very high, and the data transmits through both wireless and wired channels.

. List out the various IoT Protocol layers stack?

Ans. IoT protocols ensure the safety of data connection between linked devices and also provide data protection. They include- 

  • Datalink Layer
  • Application Layer
  • Transport Layer
  • Network Layer
  • Physical Layer

. Name the various CAN Frames in IoT?

Ans. CAN stands for Controller Area Network, and the following are the various types of CAN frames - Remote Frame, Data Frame, Overload Frame, and Error Frame.

. Define Thermocouple sensor?

Ans. It is a specific sensor helpful to measure the temperature by coupling or joining together two metal pieces. It measures the temperature between the two pieces of metals joined at one end. Moreover, it is a robust, easy-to-use, and very cost-effective temp measuring sensor that is available in different types. Further, it is best suitable for different applications like industrial, scientific, home appliances, etc.

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As a Senior Writer for HKR Trainings, Sai Manikanth has a great understanding of today’s data-driven environment, which includes key aspects such as Business Intelligence and data management. He manages the task of creating great content in the areas of Digital Marketing, Content Management, Project Management & Methodologies, Product Lifecycle Management Tools. Connect with him on LinkedIn and Twitter.

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