Micro Controller and its Application

Expected Question
1. Random access memory holds _____ bytes of storage in 8051.
a) 124
b) 128
c) 324
d) 126
2. The chip crystal oscillator holds a frequency of ____ MHz in 8051.
a) 6
b) 12
c) 18
d) 24
3. Pins from _____ are known as Port0 in 8051 Microcontroller.
a) 32-39
b) 32-37
c) 31-37
d) 31-38
4. Using port 2, the higher sequence _____ signals are multiplied.
a) Signal Bus
b) Data Bus
c) Address Bus
d) None Of these
5. Address latch enable use to distribute data through____ signal of the
port.
a) Signal Bus
b) Data Bus
c) Address Bus
d) Address-Data bus
6. ______ are used to connect to input-output ports.
a) Peripheral Devices
b) Memory Devices
c) Circuits
d) Timers
7. If pins are arranged as inputs, then it provides a ____ current at pull-up
resistors.
a) Strong
b) Weak
c) Null
d) None of these
8. ______ which alters the program for some time temporary.
a) Interrupts
b) Timers
c) Actuators
d) Shifters
9. How many interrupt signals exist in 8051?
a) 2
b) 3
c) 4
d) 5
10. To enable/disable _____interrupt, the ET1 pin is used.
a) Timer 1 overflow
b) Buses
c) Serial port
d) Timer 0 overflow
11. PS pin represents the priority level of _____ interrupt.
a) Serial Port
b) Timers
c) Buses
d) Signals
12. Program will be regained when the power is switched off is called
_____memory.
a) ROM
b) RAM
c) SRAM
d) EPROM
13. For all of the arithmetic operations and logical instructions, _____ is
used.
a) Multiplier
b) Shifter
c) Accumulator
d) None of these
14. Data point register holds ____ bit addres
a) 12
b) 14
c) 16
d) 18
15. PSW register is also called as _____ register?
a) Program
b) Shift
c) Flag
d) Right
16. Stack holds data from 00 to __ H?
a) 1F
b) FF
c) DF
d) 0F
17. Increment and decrement bits are instructions that don't ____ the PSW
Flags?
a) Moves
b) Sets
c) Adds
d) Subtracts
18. Which of the following is NOT a feature of the 8051 microcontroller?
A.128 bytes of RAM
B. Four 8-bit ports
C. Two 16-bit timers
D. 16-bit data bus
19. In the 8051, the Program Status Word (PSW) is an 8-bit register that contains status
flags. Which bit in the PSW is used to indicate a carry-out from the most significant
bit (D7) of the accumulator during an arithmetic operation?
A.C (Carry flag)
B.P (Parity flag)
C.OV (Overflow flag)
D.AC (Auxiliary Carry flag)
20. The instruction `MOV A, #55H` is an example of which addressing mode?
A.Register indirect addressing
B.Direct addressing
C.Register addressing
D.Immediate addressing
21. What is the function of the `LCALL` instruction in the 8051?
A.It is a long call instruction that pushes the current PC onto the stack and jumps to a
16-bit address.
B.It is a conditional jump instruction.
C.It is a return instruction from a subroutine.
D.It is a short call instruction that can jump to any location within the current 2K page
of memory.
22. Which of the following assembler directives is used to define an 8-bit variable in the
8051 assembly language?
A.`DB`
B.`EQU`
C.`DW`
D.`ORG`

23. Which register in the 8051 is used for serial communication?

A.TMOD
B.SBUF
C.PCON
D.TCON
 24. Which of the following is NOT a register bank in the 8051?
A. Bank 0
B.Bank 1
C.Bank 3
D.Bank 4

25. Which of the following statements about the `PCH` and `PCL` registers is correct?
A.They are special function registers (SFRs) that form the 16-bit Program Counter.
B.They are 16-bit registers used for data storage.
C.They are used for I/O port programming.
D.PCH holds the low byte and PCL holds the high byte of the program counter.

26. The `P0` port of the 8051 is a true bidirectional port, but it requires external pull-up
resistors when used as an output. Why?
A. To increase the current driving capability.
B.To provide high-frequency clock pulses.
C.Because it has open-drain outputs, which can only sink current.
D.To prevent data loss during power failure.

27. What is the purpose of the `ORL` instruction?

A. Performs a bit-wise XOR operation.
B.Rotates a byte to the left.
C.Performs a bit-wise AND operation.
D.Performs a bit-wise OR operation.

28. Which of the following is an example of an application for the 8051 microcontroller?
A.Creating high-end 3D graphics for a video game console.
B.Controlling the temperature of an industrial furnace.
C.Developing a real-time operating system for a personal computer.
D.Designing a complex database system for a large company

29. The `IC 8255` can be configured in various modes. Which mode is used for simple
I/O with no handshaking?
A.Mode 1 (Strobed I/O)
B.Mode 3
C.Mode 2 (Bidirectional Bus)
D.Mode 0 (Simple I/O)

30. What is the purpose of the `CPL A` instruction?

A.Increment the Accumulator.
B.Clear the Accumulator.
C.Complement the Accumulator.
D.Rotate the Accumulator left.

31. The 8051 has an on-chip oscillator. The frequency of the crystal connected to the
`XTAL1` and `XTAL2` pins determines the machine cycle. What is the formula for
the machine cycle duration?
A.12 / (crystal frequency)
B.2 / (crystal frequency)
C.6 / (crystal frequency)
D.1 / (crystal frequency)
32. Which of the following is a key feature of the `IC 8255` that makes it useful for
interfacing with microcontrollers?
A.It has a built-in memory bank.
B.It can be programmed to operate in various I/O modes.
C.It has a built-in A/D converter.
D.It can generate high-speed PWM signals.

33. Which of the following is a key advantage of the 8051's single-byte instructions?
A.They increase the instruction cycle time.
B.They reduce the program memory requirement.
C.They allow for complex arithmetic operations.
D.They increase the number of available registers.

34. In the `IC 8255`, which port is typically used as a control port when in Mode 1 or
Mode 2?
A.All three ports are used as control ports.
B.Port B
C.Port C
D.Port A

35. In the 8051, the `IC 8255` can be interfaced to expand the number of I/O ports. To
which 8051 port are the data pins of the 8255 typically connected?
A.Port 0
B.Port 1
C.Port 3
D.Port 2

36. What is the purpose of the `SBUF` register in the 8051?

A.It stores the interrupt flags for serial communication.
B.It is used to store the baud rate value.
C.It is a buffer for transmitting and receiving serial data.
D.It is the status register for serial communication.

37. Which of the following is a key architectural feature of the PIC microcontroller
family?
A.Complex Instruction Set Computer (CISC) architecture
B.Harvard architecture
C.RISC architecture with a large instruction set
D.Von Neumann architecture

38. The Arduino board's main microcontroller is typically from which family?
A.Intel 8051
B.PIC16F84
C.AVR (e.g., ATmega328)
D.ARM Cortex-M

39. Which of the following is a key characteristic of the Raspberry Pi compared to a

microcontroller like Arduino?
 A.It is a single-board computer capable of running a full operating system.
B.It is programmed exclusively using the Arduino IDE.
C.It is a microcontroller with a limited operating system.
D.It has a large number of digital and analog I/O pins.

40. Which of the following best defines the term 'Internet of Things' (IoT)?
A.A specialized network for industrial automation only.
B.A network of computers and servers for data storage.
C.A protocol for connecting mobile devices to the internet.
D.A network of physical objects embedded with sensors and software for data
exchange.

41. In a typical four-stage IoT architecture, which layer is responsible for data acquisition
from sensors and devices?
A.Perception layer
B.Network layer
C.Application layer
D.Cloud processing layer

42. Which instruction in the PIC microcontroller assembly language is used to move data
from the W register to the file register?
A.MOVLW
B.MOVFF
C.MOVWF
D.MOVF

43. Which programming language is the Arduino IDE primarily based on?
A.C++
B.Python
C.Assembly
D.C

44. The Raspberry Pi's main processor is a System on a Chip (SoC). Which type of
processor core does it primarily use?
A.Intel x86
B.PowerPC
C.ARM
D.MIPS

45. Which of the following is NOT a fundamental component of an IoT ecosystem?

A.Sensors and actuators
B.User interface
C.Connectivity
D.Standalone desktop application

46. In the PIC microcontroller, which register is used to select the RAM bank?
A.Program Counter (PC)
B.W register
C.STATUS register
D.Port register (e.g., PORTA)
47. What is the primary function of the GPIO (General Purpose Input/Output) pins on a
Raspberry Pi?
A.To interface with external hardware like sensors, LEDs, and motors.
B.To provide power to the board.
C.To connect the Raspberry Pi to the internet.
D.To provide high-speed video output.

48. What is the function of the `TRIS` register in a PIC microcontroller?

A.To store the data for a specific port.
B.To set the direction of I/O pins (input or output).
C.To enable or disable interrupts.
D.To select the clock frequency.

49. Which of the following is an example of an 'actuator' in an IoT system?

A.A temperature sensor
B.A light-emitting diode (LED)
C.A Wi-Fi module
D.A camera

50. What is a key difference between the Arduino Uno and the Raspberry Pi in terms of
their intended use?
A.Arduino is for complex web servers, and Raspberry Pi is for simple I/O tasks.
B.Arduino is a microcontroller for real-time control, while Raspberry Pi is a single-
board computer for general-purpose computing.
C.Arduino is primarily for robotics, while Raspberry Pi is for home automation.
D.There is no significant difference, they are interchangeable.