Here are IoT interview questions for fresher as well as experienced candidates to get their dream job.
1) What is the Internet Of Things (IoT)?
Internet of Things (IoT) is a network of physical objects or people called “things” that are embedded with software, electronics, network, and sensors that allow these objects to collect and exchange data. The goal of IoT is to extend to internet connectivity from standard devices like computer, mobile, tablet to relatively dumb devices like a toaster.
2) Explain Raspberry Pi
Raspberry Pi is a computer which is capable of doing all the operations like a conventional computer. It has other features such as onboard WiFi, GPIO pins, and Bluetooth in order to communicate with external things.
3) How to run Raspberry pi in headless mode?
Raspberry pi in headless mode can be run by using SSH. The latest operating system has an inbuilt VNC server that is installed for taking remote desktop on Raspberry Pi.
4) What are the fundamental components of IoT?
The four fundamental components of an IoT system are:
- Sensors/Devices: Sensors or devices are a key component that helps you to collect live data from the surrounding environment. All this data may have various levels of complexities. It could be a simple temperature monitoring sensor, or it may be in the form of the video feed.
- Connectivity: All the collected data is sent to a cloud infrastructure. The sensors should be connected to the cloud using various mediums of communications. These communication mediums include mobile or satellite networks, Bluetooth, WI-FI, WAN, etc.
- Data Processing: Once that data is collected, and it gets to the cloud, the software product performs processing on the gathered data. This process can be just checking the temperature, reading on devices like AC or heaters. However, it can sometimes also be very complex, like identifying objects, using computer vision on video.
- User Interface: The information needs to be available to the end-user in some way, which can be achieved by triggering alarms on their phones or sending them notification through email or text message. The user sometimes might need an interface which actively checks their IoT system.
5) List layers of IoT protocol stack
Layers of IoT protocol stack are: 1) Sensing and information, 2) Network connectivity, 3) Information processing layer, 4) Application layer.
6) What are the disadvantages of IoT?
The disadvantages of IoT are:
- Security: IoT technology creates an ecosystem of connected devices. However, during this process, the system may offer little authentication control despite sufficient cybersecurity measures.
- Privacy: The use of IoT, exposes a substantial amount of personal data, in extreme detail, without the user’s active participation. This creates lots of privacy issues.
- Flexibility: There is a huge concern regarding the flexibility of an IoT system. It is mainly regarding integrating with another system as there are many diverse systems involved in the process.
- Complexity: The design of the IoT system is also quite complicated. Moreover, it’s deployment and maintenance also not very easy.
- Compliance: IoT has its own set of rules and regulations. However, because of its complexity, the task of compliance is quite challenging.
7) Define Arduino
Arduino is a free electronics platform having easy to use hardware and software. It has a microcontroller capable of reading input from sensors to control the motors programmatically.
8) List mostly used sensors types in IoT
Mostly used sensor types in IoT are:
- Smoke sensor
- Pressure sensor
- Motion detection
- Gas sensor
- Proximity sensor
- IR sensors
9) Mention the basic difference between IoT and sensor businesses?
A sensor business does not need an active internet connection to work. Internet of Things requires a control side to work.
10) What is Bluegiga APX4 protocol?
The Bluegiga APX4 is a solution that supports both the WiFI and BLE platform, and it is based on a 450MHz ARM9 processor.
11) What is Pulse Width Modulation?
PWM or Pulse Width Modulation is a variation of how much time the signal is high in an analog fashion. The signal can be high or low, and the user can even change the proportion of the time.
12) Mention applications of PWM in IoT
Applications of PWM in IoT are controlling the speed of DC motor, Controlling the direction of a servo moto, Dimming LED, etc.
13) List available wireless communications boards available in Raspberry Pi?
Wireless communications boards available in Raspberry Pi are 1) WiFi and 2) BLE/Bluetooth.
14) What are the functions used to read analog and digital data from a sensor in Arduino?
Functions used to read analog and digital data from a sensor in Arduino are: digitalRead() and digitalWrite().
15) What is Bluetooth Low Energy?
Bluetooth Low Energy is a wireless PAN (Personal Area Network) technology. It uses less power to transmit long-distance over a short distance.
16) Define MicroPython
MicroPython is a Python implementation, which includes a small subset of its standard library. It can be optimized to run on the ModeMCU microcontroller.
17) List available models in Raspberry Pi
Models of Raspberry Pi are:
- Raspberry Pi 1 Model B
- Raspberry Pi 1 Model B+
- Raspberry Pi 1 Model A
- Raspberry Pi Zero
- Raspberry Pi 3 Model B
- Raspberry Pi 1model A+
- Raspberry Pi Zero W
- Raspberry Pi 2
18) What are the challenges of IoT?
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
19) Mention some of the commonly used water sensors
The commonly used water sensors are:
- Turbidity sensor
- Total organic carbon sensor
- pH sensor
- Conductivity sensor
20) What are mostly used IoT protocols?
The mostly used IoT protocols are:
- Very Simple
- Control Protocol (VSCP)
- Data Distribution Service (DDS)
- MQTT protocol
- Simple Text Oriented Messaging Protocol(STOMP)
21) What are IoT publishers?
IoT Publishers are sensors that send real-time data to intermediate devices or middleware.
22) What is a library in Arduino?
Arduino library is a collection of code that is already written for controlling module or sensor.
23) Mention some of the wearable Arduino boards
Wearable Arduino boards are:
- Lilypad Arduino main board
- Lilypad Arduino simple
- Lilypad Arduino simple snap
- Lilypad Arduino USB
24) What is replication?
Replication is the act of syncing data between two or more servers.
25) What is IoT Thingworx?
Thingworx is a platform for the fast development and deployment of connected devices. It is a collection of integrated IoT development tools that support analysis, production, property, and alternative aspects of IoT development.
26) What is Salesforce IoT Cloud?
The Salesforce IoT Cloud is an online platform for storing and processing IoT information.
It is an assortment of various application development elements, which are called lightning.
This program gathers information from websites, devices, customers, and partners. It then triggers actions for period responses.
27) Explain IoT GE-PREDIX
GE or General Electric Predix is a software for the information assortment from industrial instruments. It offers a PaaS which allows users performance management and operation optimization facility. It connects instrumentation, people, and information in an exceedingly conventional technique.
28) List out Some popular companies are working on IoT
Popular companies working on IoT are: 1) Philips, 2) LG, 3) Google, 4) Apple and 5) Samsung.
29) What are various types are of CAN Frame?
Various types of CAN frames are: 1) data frame, 2) request frame, 3) error frame, and 4) overload frame.
30) What is the main difference between floating CPU and fixed-point CPU?
Floating CPU can take floating value directly, whereas fixed CPU is converted to integer format. Thereby, it leads to the loss of some resolution.
31) Define GPIO
GPIO is a programmable pin that can be used to control input or output pins programmatically.
32) Explain Android things
Android things is an Android-based OS that is built for embedded devices.
33) What is the aim of airflow sensors?
The main aim of airflow sensors is to measure the air level in the soil. This sensor enables one to measure it dynamically, from one location, or multiple locations of the garden.
34) Mention suitable databases for IoT
Suitable databases for IoT are:
- influx DB
- Apache Cassandra
35) Why use the scheduler in RTOS?
Scheduler in RTOS is used for switching one task to another.
36) Mention real-time usage of Raspberry pi
- Home a
- Portable webserver
- manipulating the
- Internet radio
37) Define IoT Contiki
IoT Contiki is software that targets explicitly little devices connected with the Internet. It is used with process power bandwidth, power, and restricted memory. Contiki helps for the management of programs, resources, processes, communication, and memory.
38) What is data in IoT?
Data in IoT refers to the information that is collected by the installed devices at any building.
39) List majorly used IoT controllers by industries
Majorly used IoT controllers by industries are: 1) Siemens IoT 2020 and 2) Arduino.
40) What is a crystal oscillator? .
A crystal oscillator is the main part of the microprocessor. It executes every single pulse one instruction in CPU.
41) What is the importance of the Internet of Everything?
Internet of Everything is important because:
- It brings together people, processes, things, and data to make network connections valuable and relevant.
- It converts the information into actions to create new capabilities and opportunities for businesses.
42) What is WSN?
The full form of WSN is Wireless Sensor Network. It is a network of notes, design to observe and to study physical parameters of the application.
43) What is Zigbee?
Zigbee is the same like Bluetooth. It used in a complex system for low power operation, robustness, and high security.
44) What is Z-Wave?
Z-Wave is an IoT technology that uses low power RF communication. It is designed for home automation products like lamp controllers and sensors.
45) How to install a new library in Arduino?
A new library in Arduino can be installed by selecting the library from the sketch option in Toolbar.
46) What is MQTT?
The full form of MQTT is Message Queue Telemetry Transport Protocol. It is a messaging protocol that is used for tracking devices in IoT.
47) Name some important IoT hardware
IoT hardware includes varieties of devices like router, bridge, sensor, etc.
48) What are the operating systems supported by Pi?
Operating systems supported by Pi are:
- Open ELEC (Open Embedded Linux Entertainment center)
- RISC OS
- OSMC (Open Source Media Centre)
- Windows IoT Core
49) How to reduce the size of the sketch?
Reducing the size of the sketch is can be reduced by removing unwanted libraries from the code and make code short and simple.
50) What are the various types of antennas designed for IoT devices?
Various types of antennas designed for IoT devices are:
- Chip Antenna
- PCB Antenna
- Wire Antenna
- Proprietary Antenna
- Whip Antenna