Explore topic-wise MCQs in 8051 Microcontroller.

This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your 8051 Microcontroller knowledge and support exam preparation. Choose a topic below to get started.

1.

WHICH_OF_THE_FOLLOWING_INSTRUCTION_CAN_BE_USED_TO_TOGGLE_A_BIT_OF_THE_PORT??$

A. SBI
B. CBI
C. SBI & CBI
D. None of the mentioned
Answer» D. None of the mentioned
Discussion
2.

WHICH_OF_THE_FOLLOWING_COMES_UNDER_THE_INDEXED_ADDRESSING_MODE??$

A. MOVX A, @DPTR
B. MOVC @A+DPTR,A
C. MOV A,R0
D. MOV @R0,A
Answer» C. MOV A,R0
Discussion
3.

What is the main function of the SBIC instruction?$

A. it is used to clear a particular bit of a port
B. it is used to jump unconditionally
C. it is used to skip the instruction if a particular bit of a port is zero
D. none of the mentioned
Answer» D. none of the mentioned
Discussion
4.

Is_this_a_valid_statement?$

A.
B. yes
C. no
Answer» C. no
Discussion
5.

Instruction CBI PORTB,1 mean?

A. clearing the PORTB register
B. clearing the first bit of the PORTB register
C. setting the PORTB register
D. setting the first bit of the PORTB register
Answer» C. setting the PORTB register
Discussion
6.

What is the advantage of register indirect addressing mode?

A. it makes use of registers R0 and R1
B. it uses the data dynamically
C. it makes use of operator @
D. it is easy
Answer» C. it makes use of operator @
Discussion
7.

Which of the following is correct about the SBIS instruction?

A. it is used to the monitor the status of the HIGH for the single bit of a port
B. it is a byte oriented instruction
C. It is a 4 byte instruction
D. all of the mentioned
Answer» B. it is a byte oriented instruction
Discussion
8.

Which operator is the most important while assigning any instruction as register indirect instruction?

A. $
B.
C. @
Answer» D.
Discussion
9.

Which of the following is not a single bit instruction in AVR?

A. SBI
B. PORT
C. CBI
D. All of the mentioned
Answer» C. CBI
Discussion
10.

Which addressing mode is used in pushing or popping any element on or from the stack?

A. immediate
B. direct
C. indirect
D. register
Answer» C. indirect
Discussion
11.

All series of AVR has 8 pins in all of their ports?

A. true
B. false
C. none of the mentioned
D. can’t be determined
Answer» C. none of the mentioned
Discussion
12.

Which instruction is used to check the status of a single bit?

A. MOV A,P0
B. ADD A,05H
C. JNB PO.0, label
D. CLR P0.05H
Answer» D. CLR P0.05H
Discussion
13.

Which of the following registers are not bit addressable?

A. SCON
B. PCON
C. A
D. PSW
Answer» C. A
Discussion
14.

On reset DDR registers of all ports are set to:

A. 0
B. 1
C. None of the mentioned
D. 0 & 1
Answer» B. 1
Discussion
15.

Which of the ports act as the 16 bit address lines for transferring data through it?

A. PORT 0 and PORT 1
B. PORT 1 and PORT 2
C. PORT 0 and PORT 2
D. PORT 1 and PORT 3
Answer» D. PORT 1 and PORT 3
Discussion
16.

The data will not go from the port registers to the pin unless:

A. DDR register of that port is set to 0
B. PORT register of that port is set to 1
C. DDR register of that port is set to 1
D. PORT register of that port is set to 0
Answer» D. PORT register of that port is set to 0
Discussion
17.

Which out of the four ports of 8051 needs a pull-up resistor for using it is as an input or an output port?

A. PORT 0
B. PORT 1
C. PORT 2
D. PORT 3
Answer» B. PORT 1
Discussion
18.

To initialize any port as an output port what value is to be given to it?

A. 0xFF
B. 0x00
C. 0x01
D. A port is by default an output port
Answer» E.
Discussion