The below given questions are MCQ's for Microcontroller and Microprocessor subject which are taken from the books kindly use this for exam preparations
a) 2
b) 0
c) 1
d) 3
Answer:C)1
2. The instruction that subtracts 1 from the contents of the specified register/memory location is
a) INC
b) SUBB
c) SUB
d) DEC
Answer:D)DEC
3. The instruction that enables subtraction with borrow is
a) DEC
b) SUB
c) SBB
d) None of the mentioned
Answer:C)SBB
4. The flag that acts as Borrow flag in the instruction, SBB is
a) direction flag
b) carry flag
c) parity flag
d) trap flag
Answer:B)Carry flag
5. In general, the source operand of an instruction can be
a) memory location
b) register
c) immediate data
d) all of the mentioned
Answer:D) All of the mentioned
6. In general, the destination operand of an instruction can be
a) memory location
b) register
c) immediate data
d) memory location and register
Answer:D) Memory location and register
7. The instruction, CMP to compare source and destination operands it performs
a) addition
b) subtraction
c) division
d) multiplication
Answer:B) Subtraction
8. During comparison operation, the result of comparing or subtraction is stored in
a) memory
b) registers
c) stack
d) no where
Answer:D)No where
During comparison process we didn't store anywhere.
9. The interrupt request that is independent of IF flag is
A.NMI
B.TRAP
C.Divide by zero
D.All of the mentioned
Answer:D.All of the mentioned
10. In reading the columns of a matrix, if no key is pressed we should get all in binary notation
a)0
b)1
c)F
d)7
Answer:B)1
11. Which instruction is used to check the status of a single bit?
Answer:JNB
12. What are optoisolators?
Answer: It is a device that can be used as an electromagnetic relay without a driver.
13. Which among the below stated registers does not belong to the category of special function registers?
A)TCON&TMOD
B)TH0&TL0
C)P0&P1
D)SP&PC
Answer:D)SP&PC
14.which special function registers play a vital role in the timer/counter mode selection process by allocating the bits in it?
A.TMOD
B.TCON
C.SCON
D.PCON
Answer:A)TMOD
15. The number of priority levels that each interrupt of 8051 have is
A.1
B.2
C.3
D.4
Answer:B)2
16.In ADC0808/0809 IC which pin is used to select step size?
A.Vref
B.Vin
C.Vref/2&Vin
D.None of the mentioned
Answer:A)Vref
17. Which register is used to make the interrupt level or an edge triggered pulse?
A.TCON
B.IE
C.IPR
D.SCON
Answer:A)TCON
18. The contents of the accumulator after this operation
MOV A,#2BH
ORL A,00H
will be:
A.1BH
B.2BH
C.3BH
D.4BH
Answer:B)2BH
19. Which of the following comes under the indexed addressing mode?
A)MOVX A,@DPTR
B)MOVX @A+DPTR,A
C)MOV A,R0
D)MOV @R0,A
Answer:B)MOVX @A+DPTR,A
20. How many bytes of BIT addressable memory having 8051 microprocessor
Answer:16 Bytes
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