8085 Microprocessor MCQ set 1 with answer

1. The 8085 has two registers known as primary data pointers. These are registers
   A. B and C
   B. D and E
   C. H and L
   D. C and D
   ANSWER: C
2. In 8085, the DAA instruction is used for
   A. Direct Address Accumulator
   B. Double Add Accumulator
   C. Decimal Adjust Accumulator
   D. Direct Access Accumulator.
   ANSWER: C
3. The description of a program counter (PC) in 8085 microprocessor is
   A. An up/down counter
   B. An 8-bit register.
   C. Initialized automatically by microprocessor.
   D. Used to point to stack memory area.
   ANSWER: A
4. An example of 8085-instruction that uses direct addressing is
   A. RLC
   B. STA
   C. RRC
   D. CMA
   ANSWER: B
5. Addressing mode used in instruction PUSH B is
   A. Direct
   B. Register
   C. Register indirect
   D. Immediate
   ANSWER: B
6. Which one of the following is not a vectored interrupt?
   A. INTR
   B. TRAP
   C. RST6.5
   D. RST7.5
   ANSWER: A
7. The power failure alarm must be connected to which one of the following inputs of 8085?
   A. INTR
   B. TRAP
   C. HOLD
   D. RST7.5
   ANSWER: B
8. Find the odd one out
   A. EQU
   B. MOV
   C. CMA
   D. DAA
   ANSWER: A (NOT AVAIL ABLE IN 8085)
9. To initiate DMA data transfer the signal to be sent to the CPU is
   A. HOLD
   B. READY
   C. INTR
   D. None of these
   ANSWER: A
10. READY signal in 8085 is useful when the CPU communicates with
    A. A slow peripheral device
    B. A fast peripheral device
    C. A DMA controller chip
    D. A PPI chip
    ANSWER: A
11. In an 8085, what is the content of the Instruction Register (IR)?
    A. Op-code for the instruction being executed
    B. Operand for the instruction being executed
    C. Op-code for the instruction to be executed next
    D. Operand for the instruction to be executed next
    ANSWER: A
12. Which interrupt has the highest priority?
    A. INTR
    B. TRAP
    C. RST6.5
    D. RST7.5
    ANSWER: B
13. In 8085 name the 16 bit registers?
    A. Stack pointer
    B. Program counter
    C. A & B
    D. None of these
    ANSWER: C
14. In an 8085, after the execution of XRA A instruction
    A. The carry flag is set
    B. The accumulator contains FFH
    C. The content of accumulator is shifted by one
    D. The zero flag is set
    ANSWER: D (content of Accumulator becomes zero)
15. The number of flags of the 8085 microprocessor is
    A. 6
    B. 5
    C. 4
    D. 3
    ANSWER: B
16. Why 8085 processor is called an 8 bit processor?
    A. Because 8085 processor has 8 bit ALU
    B. Because 8085 processor has 8 bit data bus
    C. A & B
    D. None of these
    ANSWER: C
17. Which stack is used in 8085?

A. FIFO
B. LIFO
C. FILO
D. LILO
ANSWER: B

18. Accumulator is
    A. Counter
    B. Register
    C. Keyboard
    D. None
    ANSWER: B
19. The contents of Program Counter (PC), when the processor is reading from 2FFF H location, will be
    A. 2FFE H
    B. 2FFF H
    C. 3000 H
    D. 3001 H
    ANSWER: C (It will be incremented by one automatically
20. In 8085A microprocessor ALE signals made high to
    A. Enable the data bus to be used as low order address bus
    B. To latch data D0-D7 from data bus
    C. To disable data bus
    D. To achieve all the functions listed above
    ANSWER: B
21. What does microprocessor speed depends on?
    A. Clock
    B. Data bus width
    C. Address bus width
    D. None
    ANSWER: A
22. The number of register pairs of 8085 microprocessor is
    A. 3
    B. 4
    C. 2
    D. 5
    ANSWER: A
23. PSW in the 8085 microprocessor is a
    A. 8-bit register
    B. 16-bit register
    C. 4-bit register
    D. 32-bit register
    ANSWER: B
24. The address lines required for 16K byte memory chip are
    A. 13
    B. 14
    C. 15
    D. 16
    ANSWER: B
25. In 8085 the addressable memory is
    A. 64kB
    B. 1MB
    C. 4kB
    D. 16kB
    ANSWER: A