Sunday, July 27, 2025

ECE - MC - MICROCONTROLLER MCQ QUESTIONS - MC MCQ QUESTIONS

 

ECE - MC - MICROCONTROLLER MCQ QUESTIONS - MC MCQ QUESTIONS

### ✅ **UNIT I: ARCHITECTURE OF 8051 MICROCONTROLLER (20 MCQs)**

1. **Which company developed the 8051 microcontroller?**
   A) Intel
   B) Motorola
   C) AMD
   D) Atmel
   **Answer: A**

2. **8051 is a \_\_\_\_ bit microcontroller.**
   A) 4
   B) 8
   C) 16
   D) 32
   **Answer: B**

3. **Microprocessor vs Microcontroller: Which has on-chip memory and I/O ports?**
   A) Microprocessor
   B) Microcontroller
   C) Both
   D) None
   **Answer: B**

4. **Which block controls the sequence of execution in 8051?**
   A) ALU
   B) Timer
   C) Program Counter
   D) RAM
   **Answer: C**

5. **The ALU in 8051 is responsible for:**
   A) Memory addressing
   B) Logical and arithmetic operations
   C) Communication
   D) Program storage
   **Answer: B**

6. **How many I/O ports does the 8051 have?**
   A) 2
   B) 3
   C) 4
   D) 5
   **Answer: C**

7. **Total number of pins in 8051 DIP package is:**
   A) 20
   B) 30
   C) 40
   D) 44
   **Answer: C**

8. **PSW register in 8051 stands for:**
   A) Program Status Word
   B) Primary Status Window
   C) Program Stack Width
   D) Processor Status Word
   **Answer: A**

9. **Which register is incremented automatically during program execution?**
   A) PSW
   B) PC
   C) Stack Pointer
   D) ACC
   **Answer: B**

10. **What is the function of the Stack in 8051?**
    A) Handles I/O operations
    B) Stores immediate data
    C) Temporary storage during interrupts
    D) Controls timers
    **Answer: C**

11. **Special Function Registers (SFRs) are located in which memory area?**
    A) ROM
    B) External RAM
    C) Internal RAM
    D) Code memory
    **Answer: C**

12. **Which port is used to interface external memory?**
    A) P0 and P2
    B) P1 and P3
    C) P2 and P3
    D) P0 and P1
    **Answer: A**

13. **The timer in 8051 is used for:**
    A) RAM expansion
    B) I/O programming
    C) Delay generation
    D) Address decoding
    **Answer: C**

14. **Which of the following is NOT a feature of 8051?**
    A) Serial port
    B) Timers
    C) Multiplication instruction
    D) 32-bit ALU
    **Answer: D**

15. **Interrupts in 8051 are used for:**
    A) Resetting memory
    B) Parallel processing
    C) Handling events
    D) Timer reset
    **Answer: C**

16. **How many interrupts are there in 8051?**
    A) 3
    B) 4
    C) 5
    D) 6
    **Answer: D**

17. **Port 0 of 8051 can be used as:**
    A) Output only
    B) Input only
    C) Bidirectional I/O
    D) Serial communication
    **Answer: C**

18. **Which register indicates current status of ALU operations?**
    A) PSW
    B) PC
    C) ACC
    D) DPTR
    **Answer: A**

19. **Which of the following is used for serial communication?**
    A) Timer
    B) Port 0
    C) UART
    D) Port 1
    **Answer: C**

20. **External memory is accessed using which signal?**
    A) ALE
    B) PSEN
    C) EA
    D) All of the above
    **Answer: D**


### ✅ **UNIT II: 8051 INSTRUCTION SET AND PROGRAMMING (20 MCQs)**

1. **Which instruction is used to transfer data from one register to another in 8051?**
   A) MOV
   B) ADD
   C) SUBB
   D) CJNE
   **Answer: A**

2. **The instruction `ADD A, R1` performs:**
   A) Subtraction
   B) Multiplication
   C) Addition of accumulator and R1
   D) None
   **Answer: C**

3. **Which instruction is used to jump unconditionally in 8051?**
   A) SJMP
   B) CJNE
   C) JNC
   D) JZ
   **Answer: A**

4. **Which instruction is used to multiply two numbers?**
   A) ADD
   B) MUL AB
   C) SUBB
   D) DIV AB
   **Answer: B**

5. **Logical instruction `ANL A, R2` performs:**
   A) Logical OR
   B) Logical AND
   C) Logical XOR
   D) Logical NOT
   **Answer: B**

6. **Which instruction is used to compare two values and jump if not equal?**
   A) JZ
   B) CJNE
   C) MOV
   D) SJMP
   **Answer: B**

7. **The maximum size of the immediate data in 8051 is:**
   A) 4 bits
   B) 8 bits
   C) 12 bits
   D) 16 bits
   **Answer: B**

8. **Which instruction divides the accumulator by register B?**
   A) DIV AB
   B) SUB AB
   C) MUL AB
   D) MOV AB
   **Answer: A**

9. **The instruction `CLR A` does what?**
   A) Clears Port A
   B) Clears all bits of the accumulator
   C) Clears memory
   D) Clears flag
   **Answer: B**

10. **The bit manipulation instruction used to complement a bit is:**
    A) SETB
    B) CLR
    C) CPL
    D) MOV
    **Answer: C**

11. **Instruction `MOVX` is used for:**
    A) External memory access
    B) Bit manipulation
    C) Arithmetic operation
    D) Logical operation
    **Answer: A**

12. **How many addressing modes are available in 8051?**
    A) 2
    B) 4
    C) 5
    D) 6
    **Answer: D**

13. **In which addressing mode is the operand specified within the instruction?**
    A) Register
    B) Immediate
    C) Indirect
    D) Direct
    **Answer: B**

14. **`MOV A, #55H` is an example of:**
    A) Direct addressing
    B) Immediate addressing
    C) Register indirect addressing
    D) Relative addressing
    **Answer: B**

15. **Time delay routines in 8051 are created using:**
    A) Timers only
    B) Loops and NOPs
    C) Interrupts
    D) UART
    **Answer: B**

16. **To add two 16-bit numbers in 8051, you need to:**
    A) Use ADD instruction twice with carry
    B) Use only one ADD
    C) Use MOV
    D) Use NOP
    **Answer: A**

17. **Which instruction checks if a bit is 1 and skips the next instruction if false?**
    A) JB
    B) JNB
    C) JZ
    D) JC
    **Answer: A**

18. **Instruction `DJNZ` is used for:**
    A) Delay creation
    B) Decrement and jump if not zero
    C) Compare and jump
    D) Bit clearing
    **Answer: B**

19. **BCD to HEX conversion is commonly done using:**
    A) MOV & ADD
    B) Logical and arithmetic instructions
    C) Timers
    D) Interrupts
    **Answer: B**

20. **To find the smallest number among given values in assembly, we use:**
    A) Compare and conditional jump
    B) MUL AB
    C) INC
    D) PUSH and POP
    **Answer: A**



### ✅ **UNIT III: PERIPHERALS OF 8051 (20 MCQs)**

1. **Which of the following ports of 8051 is used for interrupt and serial communication?**
   A) Port 0
   B) Port 1
   C) Port 2
   D) Port 3
   **Answer: D**

2. **Each I/O port of 8051 is of size:**
   A) 4-bit
   B) 6-bit
   C) 8-bit
   D) 16-bit
   **Answer: C**

3. **The address range of SFRs is:**
   A) 00H to FFH
   B) 00H to 7FH
   C) 80H to FFH
   D) 00H to 0FH
   **Answer: C**

4. **Which port requires external pull-up resistors in 8051?**
   A) Port 0
   B) Port 1
   C) Port 2
   D) Port 3
   **Answer: A**

5. **Bit addressable area of 8051 starts from:**
   A) 00H
   B) 20H
   C) 30H
   D) 80H
   **Answer: B**

6. **Which instruction is used to set a single bit in I/O port?**
   A) SETB
   B) MOV
   C) CLR
   D) CPL
   **Answer: A**

7. **Timer 0 and Timer 1 in 8051 are:**
   A) 4-bit
   B) 8-bit
   C) 16-bit
   D) 32-bit
   **Answer: C**

8. **How many timer/counters are present in 8051?**
   A) 1
   B) 2
   C) 3
   D) 4
   **Answer: B**

9. **Which SFR is used to control timer mode?**
   A) TMOD
   B) TCON
   C) PCON
   D) IE
   **Answer: A**

10. **Timer Mode 2 in 8051 is:**
    A) 13-bit
    B) 16-bit
    C) 8-bit auto-reload
    D) 32-bit
    **Answer: C**

11. **SBUF is used for:**
    A) Bit manipulation
    B) Serial communication
    C) Stack operations
    D) Timer operation
    **Answer: B**

12. **8051 uses which standard for serial communication?**
    A) USB
    B) RS232
    C) SPI
    D) I2C
    **Answer: B**

13. **The register that holds the baud rate settings is:**
    A) TMOD
    B) TH1
    C) IE
    D) TCON
    **Answer: B**

14. **Which instruction is used to transmit data via serial port?**
    A) MOV SBUF, A
    B) MOV A, SBUF
    C) SETB TI
    D) CLR RI
    **Answer: A**

15. **The TI flag is set when:**
    A) A timer overflows
    B) A bit is set
    C) A byte is transmitted
    D) An interrupt occurs
    **Answer: C**

16. **8051 has how many interrupt sources?**
    A) 2
    B) 3
    C) 5
    D) 6
    **Answer: D**

17. **Which interrupt has the highest priority by default?**
    A) Serial
    B) External 0
    C) Timer 0
    D) Timer 1
    **Answer: B**

18. **The IE register is used to:**
    A) Enable or disable interrupts
    B) Configure timers
    C) Clear the accumulator
    D) Set the serial baud rate
    **Answer: A**

19. **Which pin of 8051 is used for external interrupt 0?**
    A) P3.3
    B) P3.2
    C) P3.4
    D) P3.5
    **Answer: B**

20. **Which register controls interrupt priority?**
    A) IE
    B) IP
    C) PSW
    D) PCON
    **Answer: B**



### ✅ **UNIT IV: INTERFACING TECHNIQUES (20 MCQs)**

1. **Which IC is used for parallel peripheral interfacing with 8051?**
   A) 8251
   B) 8253
   C) 8255
   D) 8279
   **Answer: C**

2. **How many ports are there in 8255?**
   A) 1
   B) 2
   C) 3
   D) 4
   **Answer: C**

3. **How many modes are supported by 8255?**
   A) 1
   B) 2
   C) 3
   D) 4
   **Answer: C**

4. **Which mode of 8255 is used for handshake input/output?**
   A) Mode 0
   B) Mode 1
   C) Mode 2
   D) BSR Mode
   **Answer: B**

5. **Which mode allows bidirectional data transfer in 8255?**
   A) Mode 0
   B) Mode 1
   C) Mode 2
   D) BSR
   **Answer: C**

6. **Relays are used to interface:**
   A) Low power devices
   B) High power AC/DC devices
   C) Sensors
   D) Microcontrollers
   **Answer: B**

7. **Which component is used for temperature sensing?**
   A) Relay
   B) LM35
   C) LCD
   D) 8255
   **Answer: B**

8. **Which display uses 7 segments to show digits?**
   A) LCD
   B) LED matrix
   C) 7-segment display
   D) OLED
   **Answer: C**

9. **Which pin in 16x2 LCD selects command or data mode?**
   A) VSS
   B) RS
   C) E
   D) D4
   **Answer: B**

10. **Which pin enables LCD operation?**
    A) RS
    B) RW
    C) E
    D) VSS
    **Answer: C**

11. **Keyboard interfacing is based on:**
    A) ADC
    B) Matrix scanning
    C) Timer
    D) PWM
    **Answer: B**

12. **How many rows and columns are there in 4x4 keypad?**
    A) 2 rows, 2 columns
    B) 4 rows, 4 columns
    C) 8 rows
    D) 3 rows, 4 columns
    **Answer: B**

13. **Stepper motor rotates in:**
    A) Continuous mode
    B) Discrete steps
    C) Random angle
    D) Vibration
    **Answer: B**

14. **Which is used to convert analog signal to digital?**
    A) DAC
    B) PWM
    C) ADC
    D) RTC
    **Answer: C**

15. **Which component is used to interface analog output devices like speakers?**
    A) ADC
    B) DAC
    C) LCD
    D) LED
    **Answer: B**

16. **PWM is generally used for controlling:**
    A) Relays
    B) Timers
    C) DC motors
    D) RAM
    **Answer: C**

17. **What does PWM stand for?**
    A) Pulse Width Memory
    B) Pulse Wide Mode
    C) Pulse Width Modulation
    D) Programmable Wave Modulation
    **Answer: C**

18. **The interface used to control AC loads safely is:**
    A) Keyboard
    B) DAC
    C) Relay
    D) LCD
    **Answer: C**

19. **Which of these is NOT used for interfacing with 8051?**
    A) LCD
    B) ADC
    C) Hard disk
    D) Stepper motor
    **Answer: C**

20. **Sensor interfacing involves conversion of:**
    A) Analog to analog
    B) Digital to analog
    C) Analog to digital
    D) None
    **Answer: C**




### ✅ **UNIT V: ADVANCED MICROCONTROLLERS (20 MCQs)**

1. **Which of the following is an open-source microcontroller platform?**
   A) 8051
   B) ARM7
   C) Arduino
   D) PIC
   **Answer: C**

2. **The Arduino Uno board is based on which microcontroller?**
   A) AT89C51
   B) ATmega328P
   C) PIC16F877A
   D) ATmega2560
   **Answer: B**

3. **Which programming language is commonly used in Arduino IDE?**
   A) Python
   B) Java
   C) C/C++
   D) Assembly
   **Answer: C**

4. **What type of port is used to upload code into Arduino?**
   A) VGA
   B) Ethernet
   C) USB
   D) HDMI
   **Answer: C**

5. **What is the voltage level of digital I/O pins in Arduino Uno?**
   A) 1.8V
   B) 3.3V
   C) 5V
   D) 12V
   **Answer: C**

6. **Which of the following is a feature of Arduino?**
   A) Complex architecture
   B) Needs external programmer
   C) Open-source hardware
   D) Cannot be used in IoT
   **Answer: C**

7. **Which one is an IoT communication protocol?**
   A) I2C
   B) SPI
   C) MQTT
   D) USB
   **Answer: C**

8. **Which of the following is not an IoT device?**
   A) Smart thermostat
   B) Smart light bulb
   C) Manual switch
   D) Smart watch
   **Answer: C**

9. **In IoT, the purpose of a sensor is to:**
   A) Control data
   B) Generate software
   C) Collect data
   D) Transmit emails
   **Answer: C**

10. **Which architecture is commonly used in IoT?**
    A) 3-tier architecture
    B) Von Neumann architecture
    C) Harvard architecture
    D) Client-Server architecture
    **Answer: A**

11. **Which one of the following is a layer in IoT architecture?**
    A) Application layer
    B) Assembly layer
    C) Programming layer
    D) Compiler layer
    **Answer: A**

12. **Which of the following technologies is used in smart homes?**
    A) IoT
    B) Robotics
    C) Bioinformatics
    D) Web designing
    **Answer: A**

13. **What is the main use of actuators in IoT systems?**
    A) Sensing temperature
    B) Measuring humidity
    C) Performing physical actions
    D) Storing data
    **Answer: C**

14. **Which of the following is an example of IoT service?**
    A) Video calling
    B) Smart irrigation
    C) Text editing
    D) Gaming
    **Answer: B**

15. **Which component is not essential for a basic IoT system?**
    A) Sensor
    B) Internet
    C) Actuator
    D) Television
    **Answer: D**

16. **What is the full form of IoT?**
    A) Internet of Televisions
    B) Interface of Technology
    C) Internet of Things
    D) Interlink of Transmission
    **Answer: C**

17. **Which of the following is NOT a feature of Arduino?**
    A) Easy to program
    B) Cost-effective
    C) Proprietary hardware
    D) Open source
    **Answer: C**

18. **What is one major ethical concern in IoT?**
    A) Display resolution
    B) Memory usage
    C) Data privacy
    D) Operating speed
    **Answer: C**

19. **IoT is mostly used in which of the following sectors?**
    A) Healthcare
    B) Agriculture
    C) Home automation
    D) All of the above
    **Answer: D**

20. **Which of the following can be a node in IoT network?**
    A) Smartphone
    B) Sensor
    C) Microcontroller
    D) All of the above
    **Answer: D**




 SYLLABUS

Unit I ARCHITECTURE OF 8051 MICROCONTROLLER 

Microprocessor-Microcontroller-Comparison of Microprocessor and Microcontroller-Architecture diagram of Microcontroller 8051-Functions of each Block-Pin details of 8051-ALU-Special Function RegistersProgram Counter-PSW Register-Stack I/O Ports-Timer-Interrupt-Serial Port-External memory. 

 Unit II 8051 INSTRUCTION SET AND PROGRAMMING 

Instruction set of 8051-Classification of 8051 Instructions-Data Transfer Instructions-Arithmetic Instructions-Logical InstructionsBranching Instructions-Bit Manipulation Instructions - Different Addressing Modes of 8051-Time Delay routines. Assembly Language Programs - 16 Bit Addition -8 Bit Multiplication - BCD to HEX Code Conversion- Smallest number. 

 Unit III PERIPHERALS OF 8051

 I/O Ports - Bit Addresses for I/O Ports-I/O Port Programming-I/O bit Manipulation Programming. Timer/Counter - SFRS for Timer- Modes of Timers/countersProgramming 8051 Timer (Simple programs). Serial Communication - SFRs for Serial Communication-RS232 Standard-8051 Connection to RS 232-8051 Serial Port Programming Interrupts - 8051 Interrupts-SFRs for interrupt-Interrupt priority Interfacing Techniques 

 Unit IV INTERFACING TECHNIQUES 

IC 8255-Block diagram-Modes of 8255-8051 interfacing with 8255 Interfacing - Relay interfacing- Sensor interfacing -Seven Segment LED Display Interfacing - LCD Interfacing-Keyboard Interfacing-Stepper Motor interfacing-ADC Interfacing- DAC interfacing - DC motor Interfacing using PWM. 

Unit V ADVANCED MICROCONTROLLERS 

Arduino- General Block diagram- Features-Applications IoT- Introduction to IoT-Architecture of IoT- IoT Services and Applications – IoT Ethics. 


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ECE - MC - MICROCONTROLLER MCQ QUESTIONS - MC MCQ QUESTIONS

  ECE - MC - MICROCONTROLLER MCQ QUESTIONS - MC MCQ QUESTIONS ### ✅ **UNIT I: ARCHITECTURE OF 8051 MICROCONTROLLER (20 MCQs)** 1. **Which co...