Free Printable IoT – 100 MCQs (Topic-Wise + Exam Format)

1.

NodeMCU is based on which microcontroller?

a)

ATmega328

b)

ESP8266

c)

STM32

d)

PIC16F877A

2.

ESP8266 is mainly used for —

a)

Data storage

b)

Wi-Fi connectivity

c)

Power regulation

d)

LED control

3.

ESP32 is an advanced version of —

a)

ESP8266

b)

Arduino Uno

c)

STM32

d)

PIC Controller

4.

ESP32 supports —

a)

Wi-Fi only

b)

Wi-Fi + Bluetooth

c)

ZigBee

d)

NFC

5.

Which development board has inbuilt Wi-Fi and USB interface?

a)

NodeMCU

b)

Arduino Uno

c)

STM32F4

d)

MSP430

6.

ESP01 is a —

a)

Wi-Fi module

b)

GPS module

c)

GSM module

d)

Temperature sensor

7.

Which IDE is used for programming NodeMCU?

a)

Arduino IDE

b)

VS Code

c)

Python

d)

Sublime

8.

ESP32 has how many cores?

a)

1

b)

2

c)

3

d)

4

9.

Which pin provides serial communication in NodeMCU?

a)

D1 & D2

b)

TX & RX

c)

A0

d)

D4

10.

NodeMCU operates at voltage —

a)

3.3V

b)

5V

c)

9V

d)

12V

11.

Wi-Fi.begin() function is used to —

a)

Start Wi-Fi connection

b)

Get IP address

c)

Stop Wi-Fi

d)

Send data

12.

Wi-Fi.localIP() returns —

a)

Router name

b)

IP address

c)

Password

d)

SSID

13.

Wi-Fi.status() checks —

a)

Connection status

b)

Battery level

c)

Temperature

d)

Storage

14.

To print IP address, we use —

a)

Serial.print(WiFi.localIP())

b)

WiFi.show()

c)

Serial.WiFi()

d)

None

15.

For connecting NodeMCU to network, which two parameters are needed?

a)

SSID & Password

b)

IP & MAC

c)

DNS & Port

d)

Token & ID

16.

The command WiFi.disconnect() is used to —

a)

Reboot

b)

Disconnect Wi-Fi

c)

Reset device

d)

None

17.

The IP address of NodeMCU is displayed on —

a)

Serial Monitor

b)

LCD

c)

OLED

d)

Cloud

18.

The Wi-Fi library is used for —

a)

Wi-Fi operations

b)

Motor control

c)

EEPROM

d)

Sensor reading

19.

ESP8266 can be connected to mobile hotspot using —

a)

SSID & Password

b)

IP only

c)

Token

d)

USB cable

20.

To start serial communication, command used is —

a)

Serial.begin(9600)

b)

WiFi.begin()

c)

Start.Serial()

d)

print.Serial()

21.

In IoT, a client is —

a)

Data sending device

b)

Cloud server

c)

Router

d)

Gateway

22.

In IoT, a server is —

a)

Data receiver and processor

b)

Display

c)

Sensor

d)

Buzzer

23.

IoT communication uses —

a)

Internet

b)

Cable

c)

FM

d)

Infrared

24.

The ESP library used for web client connection —

a)

WiFiClient.h

b)

EEPROM.h

c)

Motor.h

d)

SPI.h

25.

IoT server mostly runs on —

a)

Cloud platform

b)

USB

c)

Local folder

d)

GSM

26.

HTTP uses port —

a)

80

b)

1883

c)

22

d)

21

27.

HTTPS uses port —

a)

443

b)

80

c)

23

d)

20

28.

MQTT protocol works on port —

a)

1883

b)

8080

c)

22

d)

110

29.

MQTT with SSL uses port —

a)

8883

b)

443

c)

8080

d)

21

30.

FTP uses ports —

a)

A) 20 and 21

b)

B) 25 and 26

c)

C) 443

d)

D) 80

31.

SMTP protocol is used for —

a)

Sending emails

b)

File transfer

c)

Printing

d)

Voice

32.

DNS operates on port —

a)

53

b)

80

c)

1883

d)

443

33.

Telnet runs on port —

a)

A) 23

b)

B) 25

c)

C) 110

d)

D) 22

34.

MQTT is used in IoT for —

a)

Device communication

b)

Image transfer

c)

Video streaming

d)

Data backup

35.

Port 1883 is reserved for —

a)

MQTT

b)

HTTP

c)

CoAP

d)

FTP

36.

Access Point (AP) mode means —

a)

NodeMCU creates its own Wi-Fi

b)

Connects to router

c)

Works offline

d)

No Wi-Fi

37.

Station (STA) mode means —

a)

NodeMCU connects to router

b)

Acts as router

c)

Shuts Wi-Fi

d)

Offline

38.

AP + STA combined mode is called —

a)

SoftAP + Station

b)

DoubleNet

c)

Wi-Net

d)

HotSpot

39.

WiFi.softAP() is used for —

a)

Start Access Point

b)

Station mode

c)

Send data

d)

Stop Wi-Fi

40.

WiFi.begin() is used for —

a)

Connect to router

b)

Stop Wi-Fi

c)

Display IP

d)

None

41.

WiFi.status() checks —

a)

Connection status

b)

LED

c)

Battery

d)

Display

42.

In AP mode, maximum clients —

a)

4

b)

8

c)

10

d)

2

43.

Combined AP + STA mode helps —

a)

Monitor and stay connected

b)

Disconnect internet

c)

Save power

d)

Reset

44.

WiFi.softAPdisconnect() is used to —

a)

Stop AP mode

b)

Send file

c)

Turn on AP

d)

Reset chip

45.

WiFi.localIP() gives —

a)

Device IP address

b)

Router IP

c)

DNS

d)

SSID

46.

NodeMCU can host webpage using —

a)

WebServer library

b)

EEPROM

c)

SPI

d)

Timer

47.

HTML webpage is used to —

a)

Control devices via browser

b)

Connect Bluetooth

c)

Upload code

d)

Debug

48.

HTML file is stored in —

a)

Flash (SPIFFS)

b)

RAM

c)

EEPROM

d)

Cloud

49.

To send webpage data, we use —

a)

server.send()

b)

WiFi.send()

c)

HTML.push()

d)

data.send()

50.

The function to start web server —

a)

server.begin()

b)

WiFi.begin()

c)

net.start()

d)

HTML.run()

51.

Webpage controls LED via —

a)

HTTP requests

b)

SMS

c)

Bluetooth

d)

Serial

52.

NodeMCU IP for webpage is shown on —

a)

Serial Monitor

b)

LCD

c)

Mobile app

d)

USB

53.

IoT web interface enables —

a)

Real-time device control

b)

Image edit

c)

Music play

d)

Charging

54.

CSS in IoT webpage is used for —

a)

Design and layout

b)

Connection

c)

Uploading code

d)

None

55.

Webpage communication method —

a)

HTTP

b)

SMTP

c)

FTP

d)

POP3

56.

Blynk is used for —

a)

IoT mobile app

b)

Debugging

c)

Memory test

d)

Printing

57.

Firebase is a —

a)

Real-time cloud database

b)

Sensor

c)

Hardware

d)

Server IC

58.

ThingsBoard provides —

a)

Dashboard & monitoring

b)

Music

c)

Video

d)

Display

59.

Blynk connects hardware via —

a)

Auth Token

b)

Password

c)

MAC

d)

OTP

60.

Firebase is developed by —

a)

Google

b)

Microsoft

c)

Amazon

d)

IBM

61.

Blynk communication uses —

a)

TCP/IP

b)

UDP

c)

CoAP

d)

None

62.

ThingsBoard supports —

a)

MQTT, HTTP, CoAP

b)

Only MQTT

c)

Only HTTP

d)

None

63.

Blynk app available on —

a)

Android & iOS

b)

Windows

c)

Web only

d)

Linux only

64.

Firebase dataformat —

a)

JSON

b)

XML

c)

HTML

d)

TXT

65.

Open-source IoT platforms are —

a)

Free & customizable

b)

Paid

c)

Offline only

d)

Closed

66.

66. MQTT stands for —

a)

A) Message Queue Telemetry Transport

b)

B) Multi Query Transfer Tool

c)

C) Message Quick Transfer Type

d)

D) None

67.

MQTT follows —

a)

Publish/Subscribe model

b)

Client/Server

c)

Serial link

d)

Mesh

68.

CoAP stands for —

a)

Constrained Application Protocol

b)

Common Access Protocol

c)

Cloud Application

d)

None

69.

CoAP uses —

a)

UDP

b)

TCP

c)

HTTP

d)

FTP

70.

MQTT works on —

a)

TCP

b)

UDP

c)

GSM

d)

SMS

71.

WebSocket allows —

a)

Two-way communication

b)

One-way only

c)

Text only

d)

Audio

72.

XMPP is mainly used for —

a)

Messaging

b)

Power control

c)

Sensors

d)

Video

73.

HTTP is —

a)

Request-Response protocol

b)

Streaming

c)

UDP

d)

None

74.

QoS in MQTT means —

a)

Quality of Service

b)

Queue of System

c)

Quick Operation Setup

d)

Query of Server

75.

75. MQTT Broker example—

a)

Mosquitto

b)

Firebase

c)

SQL

d)

NodeJS

76.

CoAP is used in —

a)

Low-power IoT devices

b)

Gaming

c)

Video calling

d)

Large servers

77.

HTTP vs MQTT — MQTT is —

a)

Faster and lightweight

b)

Heavy

c)

Complex

d)

None

78.

WebSocket default port —

a)

80

b)

8080

c)

21

d)

22

79.

MQTT data flow is —

a)

Publisher → Broker → Subscriber

b)

Client → Server

c)

Peer → Peer

d)

None

80.

MQTT broker acts as —

a)

Middle layer

b)

End device

c)

Display

d)

Router

81.

QoS level 0 means —

a)

At most once

b)

At least once

c)

Exactly once

d)

Never

82.

QoS level 2 means —

a)

Exactly once

b)

Once only

c)

At most once

d)

None

83.

HTTP heavier than MQTT because —

a)

Large header

b)

More delay

c)

High power use

d)

All

84.

MQTT best for —

a)

Low bandwidth networks

b)

LAN

c)

Local PC

d)

Printer

85.

MQTT packet type —

a)

PUBLISH

b)

SUBSCRIBE

c)

CONNECT

d)

All

86.

IoT stands for —

a)

Internet of Things

b)

Interface of Tech

c)

Input of Transmission

d)

None

87.

IoT allows —

a)

Device-to-device communication

b)

Human chat

c)

Bluetooth only

d)

None

88.

Example of IoT system —

a)

Smart Home

b)

Calculator

c)

TV Remote

d)

Lamp

89.

IoT enables —

a)

Remote monitoring

b)

Manual work

c)

Paper data

d)

None

90.

IoT device uses —

a)

Sensor

b)

Mouse

c)

Keyboard

d)

Printer

91.

Data in IoT is stored in —

a)

Cloud

b)

USB

c)

CD

d)

RAM

92.

ESP8266 connects to —

a)

Wi-Fi network

b)

LAN wire

c)

USB

d)

Bluetooth

93.

Arduino IDE is used for —

a)

Writing & uploading code

b)

Designing circuits

c)

Testing sensors

d)

Wi-Fi connection

94.

IoT communication is —

a)

Machine to Machine

b)

Human to Human

c)

File to File

d)

None

95.

Smart dustbin is an example of —

a)

IoT project

b)

Motor driver

c)

Sensor

d)

Cloud

96.

IoT device requires —

a)

Internet connection

b)

Fuel

c)

Optical disk

d)

SIM only

97.

ESP boards are programmed via —

a)

USB

b)

LAN

c)

GSM

d)

SD card

98.

IoT is part of —

a)

Industry 4.0

b)

Web 1.0

c)

Manual tech

d)

None

99.

Cloud in IoT used for —

a)

Data storage & processing

b)

Power

c)

Motor

d)

Network

100.

IoT sensors convert

a)

Physical data to digital

b)

Digital to audio

c)

Text to speech

d)

None

IoT – 100 MCQs (Topic-Wise + Exam Format)

Total questions: 100

Worksheet time: 50mins

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