WorksheetsMC unit-2 part1
Total questions: 20
Worksheet time: 10mins
Name
Class
Date
1.
Which instruction rotates accumulator left through carry?
a)
RL A
b)
RR A
c)
RLC A
d)
RRC A
2.
What happens when the stack overflows in8051?
a)
Corrupts internal RAM locations above 7FH
b)
Resets automatically
c)
Stops execution
d)
Generates interrupt
3.
In the instruction MOV A,#25H, which addressing mode is used?
a)
Immediate
b)
Direct
c)
Register
d)
Indirect
4.
Which instruction clears the carry flag in 8051?
a)
CLR A
b)
CLRC A
c)
CLC
d)
CLR C
5.
Which of the following is a logical instruction?
a)
ADD
b)
SUBB
c)
ORL
d)
INC
6.
To calculate a time delay using a loop which factor is MOST important?
a)
Clock frequency and number of machine cycles per instruction
b)
Size of RAM
c)
Number of I/O ports
d)
Stack pointer value
7.
DAA can adjust the value placed in Acc to decimal after operation
a)
Addition
b)
Subtraction
c)
Multiplication
d)
Division
8.
After executing MUL AB where is the lower byte of the16-bit result stored?
a)
B register
b)
Accumulator(A)
c)
R0
d)
PSW
9.
What is the addressing mode used in "MOV A 40H"?
a)
Immediate
b)
Direct
c)
Register
d)
Indirect
10.
Which instruction is used for exchanging contents of accumulator with register?
a)
SWAP
b)
XCH
c)
XRL
d)
MOVC
11.
The instruction MOV A, #55H belongs to which addressing mode?
a)
Immediate
b)
Direct
c)
Register
d)
Indirect
12.
Which instruction performs bitwise complement of accumulator?
a)
CLR A
b)
SETB A
c)
CPL A
d)
RR A
13.
The only operation not possible in bit level is
a)
data transfer
b)
Jump
c)
Logical
d)
Arithmetic
14.
If you need to find the smallest number among five numbers stored in internal RAM which structure is essential?
a)
Stack operations
b)
Loop with comparison and conditional branching
c)
Serial communication setup
d)
Timer initialization
15.
Which instruction is used for an unconditional jump in 8051
a)
SJMP
b)
CJNE
c)
DJNZ
d)
JNB
16.
What does the instruction “CPL C” do?
a)
Clears the carry flag
b)
Complements the carry flag
c)
Sets the carry flag
d)
Copies carry to accumulator
17.
The time delay subroutine is used to
a)
ON the load
b)
OFF the load
c)
Increase speed
d)
Delay the operation
18.
The instruction SETB EA is used for:
a)
Enabling serial communication
b)
Setting accumulator bit 0
c)
Enabling all interrupts
d)
Starting timer
19.
Which register is used as stack pointer in 8051?
a)
DPTR
b)
PC
c)
SP
d)
PSW
20.
Which of the following is NOT a category of 8051 instructions?
a)
Data Transfer Instructions
b)
Floating Point Instructions
c)
Arithmetic Instructions
d)
Bit Manipulation Instructions
100 %
