The 8051 Microcontroller MCQs

Question 1

Which of the following instructions will load the value 35H into the high byte of timer 0?

Accepted Answer

MOV TH0, #35H

Answer

MOV TH0, 35H

Answer

MOV T0, #35H

Answer

MOV T0, 35H

Question 2

Bit-addressable memory locations are:

Accepted Answer

20H through 2FH

Answer

10H through 1FH

Answer

30H through 3FH

Answer

40H through 4FH

Question 3

The 8-bit address bus allows access to an address range of:

Accepted Answer

00 to FFH

Answer

0000 to FFFFH

Answer

000 to FFFH

Answer

0 to FH

Question 4

The contents of the accumulator after this operation MOV A,#0BH ANL A,#2CH will be

Accepted Answer

00001000

Answer

11010111

Answer

11011010

Answer

00101000

Question 5

The start-conversion on the ADC0804 is done by using the:

Accepted Answer

SC

Answer

CS line

Answer

INTR line

Answer

V ref/2 line

Question 6

Which of the following instructions will move the contents of register 3 to the accumulator?

Accepted Answer

MOV A, R3

Answer

MOV 3R, A

Answer

MOV R3, A

Answer

MOV A, 3R

Question 7

Which of the following statements will add the accumulator and register 3?

Accepted Answer

ADD A, R3

Answer

ADD @R3, @A

Answer

ADD @A, R3

Answer

ADD R3, A

Question 8

Which of the following commands will move the number 27H into the accumulator?

Accepted Answer

MOV A, #27H

Answer

MOV A, P27

Answer

MOV A, 27H

Answer

MOV A, @27

Question 9

Which of the following commands will move the value at port 3 to register 2?

Accepted Answer

MOV R2, P3

Answer

MOV P2, R3

Answer

MOV R3, P2

Answer

MOV 3P, R2