The 8051 Microcontroller MCQs

Question 1

The number of data registers is:

Accepted Answer

32

Answer

8

Answer

16

Answer

64

Question 2

When the 8051 is reset and the EA line is LOW, the program counter points to the first program instruction in the:

Accepted Answer

external code memory

Answer

internal code memory

Answer

internal data memory

Answer

external data memory

Question 3

What is the difference between the 8031 and the 8051?

Accepted Answer

The 8031 is ROM-less.

Answer

The 8031 has no interrupts.

Answer

The 8051 is ROM-less.

Answer

The 8051 has 64 bytes more memory.

Question 4

The I/O port that does not have a dual-purpose role is:

Accepted Answer

port 1

Answer

port 0

Answer

port 2

Answer

port 3

Question 5

The contents of the accumulator after this operation MOV A,#2BH ORL A,00H will be:

Accepted Answer

2B H

Answer

1B H

Answer

3B H

Answer

4B H

Question 6

Which of the following commands will copy the contents of RAM whose address is in register 0 to port 1?

Accepted Answer

MOV P1, @ R0

Answer

MOV @ P1, R0

Answer

MOV @ R0, P1

Answer

MOV P1, R0

Question 7

Which of the following commands will copy the contents of location 4H to the accumulator?

Accepted Answer

MOV A, 04H

Answer

MOV A, L4

Answer

MOV L4, A

Answer

MOV 04H, A

Question 8

The total amount of external code memory that can be interfaced to the 8051 is:

Accepted Answer

64K

Answer

32K

Answer

128K

Answer

256K

Question 9

The ADC0804 has ________ resolution.

Accepted Answer

8-bit

Answer

4-bit

Answer

16-bit

Answer

32-bit