MCQOPTIONS
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MCQOPTIONS
This section includes 209 Mcqs, each offering curated multiple-choice questions to sharpen your Microprocessor knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
PUSH B instruction in 8085 microprocessor causes |
| A. | the contents of register B only to be copied in the stack |
| B. | the contents of register B and C to be copied in the stack |
| C. | the contents of registers B and C to be transferred in the stack and the registers get cleared |
| D. | registers B and C to be cleared |
| Answer» C. the contents of registers B and C to be transferred in the stack and the registers get cleared | |
| 102. |
(A + B + C ) is equal to |
| A. | A B C |
| B. | ABC |
| C. | A + B + C |
| D. | A + B + C |
| Answer» C. A + B + C | |
| 103. |
The following program is run on an 8085 microprocessor, |
| A. | 2050, OFFC |
| B. | 2251, OFFC |
| C. | 1025, OCCF |
| D. | 1125, OCCF |
| Answer» B. 2251, OFFC | |
| 104. |
SUB A instruction 8085 |
| A. | sets the zero flag |
| B. | resets the zero flag |
| C. | sets the carry flag |
| D. | resets the auxiliary carry flag |
| Answer» B. resets the zero flag | |
| 105. |
The negative supply voltage is used in ECL because |
| A. | the effect of noise voltage in the supply voltage can be reduced |
| B. | the effect of noise voltage in the supply voltage can be increased |
| C. | the speed will be increased |
| D. | the speed will be reduced |
| Answer» B. the effect of noise voltage in the supply voltage can be increased | |
| 106. |
AB + A C + BC is equivalent to |
| A. | AB + BC |
| B. | AB + A C |
| C. | A C + BC |
| D. | AC |
| Answer» C. A C + BC | |
| 107. |
In the Q. 159, if in addition following code exists from 0109 H onwards |
| A. | 40 H |
| B. | 20 H |
| C. | 60 H |
| D. | 42 H |
| Answer» D. 42 H | |
| 108. |
The advantage of active pull-up over passive pull-up facility in the logic gate is |
| A. | increased delay |
| B. | reduced speed |
| C. | increased speed |
| D. | None of these |
| Answer» D. None of these | |
| 109. |
The problem of current hogging is associated with |
| A. | DCTL gates |
| B. | DTL gates |
| C. | ECL gates |
| D. | CMOS gate |
| Answer» B. DTL gates | |
| 110. |
The data bus of any microprocessor is always |
| A. | unidirectional |
| B. | bi-directional |
| C. | either unidirectional or bi-directional |
| D. | none of these |
| Answer» C. either unidirectional or bi-directional | |
| 111. |
A digital IC is known to contain circuits equivalent to about 80 gates. This IC comes under the category of |
| A. | SSI |
| B. | MSI |
| C. | LSI |
| D. | VLSI |
| Answer» B. MSI | |
| 112. |
The multiplexing of address bus and data buses is used in |
| A. | all the microprocessors |
| B. | depends on the internal architecture |
| C. | never multiplexed |
| D. | none of these |
| Answer» C. never multiplexed | |
| 113. |
The following program starts at location 0100 H |
| A. | 20 H |
| B. | 02 H |
| C. | 00 H |
| D. | FF H |
| Answer» B. 02 H | |
| 114. |
The multiplexing of address bus and data buses is used in microprocessors |
| A. | To reduce the hardware complexity |
| B. | To increase the number of pins |
| C. | To reduce the number of pins on IC |
| D. | To improve the operation |
| Answer» D. To improve the operation | |
| 115. |
A microprocessor is capable of addressing 64 K bytes of memory. Its address bus width is |
| A. | 8 |
| B. | 12 |
| C. | 16 |
| D. | 20 |
| Answer» D. 20 | |
| 116. |
Consider the sequence of 8085 instructions given below |
| A. | Contents of location 9258 are moved to the accumulator |
| B. | Contents of location 9258 are compared with the contents of the accumulator |
| C. | Contents of location 8259 are complemented and stored in location 8529 |
| D. | Contents of location 5892 are complemented and stored in location 5982 |
| Answer» B. Contents of location 9258 are compared with the contents of the accumulator | |
| 117. |
A number of 1-bit registers used in microprocessors to indicate certain conditions are usually referred to as |
| A. | shift registers |
| B. | flags |
| C. | latches |
| D. | counters |
| Answer» C. latches | |
| 118. |
ECL circuits have higher fan out because of their |
| A. | high input impedance |
| B. | low output impedance |
| C. | high input and low output impedance |
| D. | complementary outputs |
| Answer» D. complementary outputs | |
| 119. |
A memory has 16-bit address bus. How many memory locations are there? |
| A. | 64 k |
| B. | 65,536 |
| C. | 216 |
| D. | All |
| Answer» E. | |
| 120. |
Which of the following flag condition are not available in 8085 processor? |
| A. | zero flag |
| B. | parity flag |
| C. | overflow flag |
| D. | auxiliary flag |
| Answer» D. auxiliary flag | |
| 121. |
In an 8085 microprocessor, the instruction CMP B has been executed while the content of the accumulator is less than that of register B. As a result |
| A. | Carry flag will be set but Zero flag will be reset |
| B. | Carry flag will be reset but Zero flag will be set |
| C. | Both Carry flag and Zero flag will be reset |
| D. | Both Carry flag and Zero flag will be set |
| Answer» B. Carry flag will be reset but Zero flag will be set | |
| 122. |
The logic swing of a gate is about 0.8 V, this belongs to the logic family |
| A. | TTL |
| B. | NMOS |
| C. | CMOS |
| D. | ECL |
| Answer» E. | |
| 123. |
Which of the following instruction will never effect the zero flag? |
| A. | DCR reg. |
| B. | ORA reg. |
| C. | DCX rp. |
| D. | XRA reg. |
| Answer» D. XRA reg. | |
| 124. |
A microprocessor has an 8-bit opcode. The maximum possible number of opcodes for this microprocessor will be |
| A. | 256 |
| B. | 64 |
| C. | 8 |
| D. | 16 |
| Answer» B. 64 | |
| 125. |
After RESET, the CPU begins execution from memory location |
| A. | 0000H |
| B. | 0001H |
| C. | FFFFH |
| D. | 8000H |
| Answer» B. 0001H | |
| 126. |
The largest positive number that can be stored in a computer that has 16-bit word length and uses 2 s complement arithmetic is |
| A. | 32 |
| B. | 32767 |
| C. | 32768 |
| D. | 65536 |
| Answer» C. 32768 | |
| 127. |
The data lines of 8085 processor are multiplexed with |
| A. | higher order address lines |
| B. | lower order address lines |
| C. | status lines |
| D. | none of the above |
| Answer» C. status lines | |
| 128. |
Among the given array for making 16,384 bit memory, which combination is usually preferred? |
| A. | 64 row 256 column |
| B. | 256 row 64 column |
| C. | 128 row 128 column |
| D. | 512 row 32 column |
| Answer» D. 512 row 32 column | |
| 129. |
Schottky TTL is a |
| A. | non-saturated bipolar logic |
| B. | saturated bipolar logic |
| C. | high threshold logic |
| D. | None of these |
| Answer» B. saturated bipolar logic | |
| 130. |
When any arithmetic instructions such as ADD or SUB is executed the condition flag |
| A. | are always set |
| B. | are always reset |
| C. | are not affected |
| D. | are affected indicating specific conditions |
| Answer» E. | |
| 131. |
When any data transfer instruction, for transfer of data between memory and microprocessor, is executed the condition flags are |
| A. | not affected |
| B. | always set |
| C. | always reset |
| D. | affected indicating specific conditions |
| Answer» B. always set | |
| 132. |
The smallest access time among the given logic family |
| A. | TTL |
| B. | RTL |
| C. | ECL |
| D. | CMOS |
| Answer» D. CMOS | |
| 133. |
The program counter in a microprocessor |
| A. | counts the number of programs being executed on the microprocessor |
| B. | counts the number of instructions being executed on the microprocessor |
| C. | counts the number of interrupts handled by the microprocessor |
| D. | keeps the address of the next instruction to be fetched |
| Answer» E. | |
| 134. |
Which of the following is slowest and the oldest type? |
| A. | PMOS |
| B. | NMOS |
| C. | CMOS |
| D. | None |
| Answer» B. NMOS | |
| 135. |
Let the contents of the accumulator and register B be 00000100 and 01000000 respectively before execution of instruction SUB B. the contents of the accumulator after the execution of this instruction will be |
| A. | 00000100 |
| B. | 01000000 |
| C. | 11000100 |
| D. | 01001000 |
| Answer» D. 01001000 | |
| 136. |
If the minimum output voltage of a 7-bit D/A is 25 4 V, what is the smallest change in the output as the binary count increase? |
| A. | 0 2 V |
| B. | 0 5 V |
| C. | 25 9 V |
| D. | 0 1 V |
| Answer» B. 0 5 V | |
| 137. |
Let the contents of register C be 00000000 before DCR C is executed. The contents of C after the execution of this instruction will be |
| A. | 00000000 |
| B. | 11111111 |
| C. | 00000001 |
| D. | None |
| Answer» C. 00000001 | |
| 138. |
An 8-bit successive approximation A/D converter has full scale reading of 2 55V and its conversion time for an analog input of 1 V is 20 s. The conversion time for a 2V input will be |
| A. | 10 s |
| B. | 20 s |
| C. | 40 s |
| D. | 50 s |
| Answer» C. 40 s | |
| 139. |
The value of X. 1 is |
| A. | X |
| B. | X |
| C. | 1 |
| D. | 0 |
| Answer» C. 1 | |
| 140. |
Most widely used universal gate are |
| A. | OR and AND |
| B. | OR and NAND |
| C. | NOR and AND |
| D. | NOR and NAND |
| Answer» E. | |
| 141. |
An instruction which contains the data in it uses |
| A. | register addressing |
| B. | immediate addressing |
| C. | register indirect addressing |
| D. | relative addressing |
| Answer» C. register indirect addressing | |
| 142. |
Resistor free logic gate family |
| A. | CMOS |
| B. | TTL |
| C. | ECL |
| D. | HTL |
| Answer» B. TTL | |
| 143. |
The number of hardware interrupts present in 8085 microprocessor are |
| A. | 5 |
| B. | 8 |
| C. | 10 |
| D. | 16 |
| Answer» B. 8 | |
| 144. |
The number of status flags present in 8085 microprocessor are |
| A. | 8 |
| B. | 16 |
| C. | 5 |
| D. | 10 |
| Answer» D. 10 | |
| 145. |
Which of the following lists the interrupts in decreasing priority? |
| A. | TRAP, RST 5 5, RST 6 5, RST 7 5, INTR |
| B. | INTR, TRAP, RST 7 5, RST 6 5, RST 5 5 |
| C. | TRAP, RST 7 5, RST 6 5, RST 5 5, INTR |
| D. | RST 7 5, RST 6 5, RST 5 5, TRAP, INTR |
| Answer» D. RST 7 5, RST 6 5, RST 5 5, TRAP, INTR | |
| 146. |
Output Y is equal to |
| A. | (A + B) C + DE |
| B. | ABC (D + E) |
| C. | (A + B) C + D + E |
| D. | (AB + C) DE |
| Answer» B. ABC (D + E) | |
| 147. |
The Boolean expression (XYZ + YZ + XZ) after simplification |
| A. | X |
| B. | Y |
| C. | Z |
| D. | (X + Y) Z |
| Answer» E. | |
| 148. |
In an 8085 microprocessor based system the maximum possible number input/output devices can be connected using I/O mapped I/O technique is given by |
| A. | 64 |
| B. | 512 |
| C. | 56 |
| D. | 65536 |
| Answer» C. 56 | |
| 149. |
When two n-bit binary numbers are added then the sum will contain at the most |
| A. | n-bit |
| B. | (n 1)-bit |
| C. | (n + 2)-bit |
| D. | (n + n)-bit |
| Answer» C. (n + 2)-bit | |
| 150. |
The only interrupt which is edge-triggered is |
| A. | INTR |
| B. | TRAP |
| C. | RST 7 5 |
| D. | RST 5 5 |
| Answer» D. RST 5 5 | |