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This section includes 2171 Mcqs, each offering curated multiple-choice questions to sharpen your ENGINEERING SERVICES EXAMINATION (ESE) knowledge and support exam preparation. Choose a topic below to get started.
201. |
In the 8421 BCD code, the decimal number 125, is written as |
A. | 1111101 |
B. | 0001 0010 0101 |
C. | 7 D |
D. | none of these |
Answer» B. 0001 0010 0101 | |
202. |
For the given truth table, the correct Boolean expression is |
A. | A |
B. | B |
C. | C |
D. | D |
Answer» C. C | |
203. |
Which of the following logic no resistors are used? |
A. | CMOS |
B. | TTL |
C. | 4 n sec ECL |
D. | 8 sec ECL |
Answer» B. TTL | |
204. |
A carry look ahead adder is frequently used for addition because |
A. | it costs less |
B. | it is faster |
C. | it is more accurate |
D. | is uses fewer gates |
Answer» C. it is more accurate | |
205. |
Which binary subtraction is incorrect? |
A. | 100101 - 100011 = 000000 |
B. | 10000000 - 01000000 = 1000000 |
C. | 10111110.1 - 101011.11 = 110010.11 |
D. | 11111111 - 1111111 = 10000000 |
Answer» B. 10000000 - 01000000 = 1000000 | |
206. |
A (A + B) = |
A. | A |
B. | B |
C. | A̅ |
D. | B̅ |
Answer» B. B | |
207. |
Find the FSV (full scale voltage) in a 6 bit R-2R ladder D/A converter has a reference voltage of 6.5 V. |
A. | 6.4 V |
B. | 0.1 V |
C. | 7 V |
D. | 8 V |
Answer» B. 0.1 V | |
208. |
BCD numbers are useful whenever |
A. | binary to hexadecimal conversion is desired |
B. | binary to BCD conversion is desired |
C. | decimal information is transferred into or out of a digital system |
D. | none of the above |
Answer» D. none of the above | |
209. |
The high voltage level of a digital signal in positive logic is |
A. | 1 |
B. | 0 |
C. | either 1 or 0 |
D. | -1 |
Answer» B. 0 | |
210. |
AECF1₁₆ + 15ACD₁₆ = __________ . |
A. | C47BB₁₆ |
B. | C47BE₁₆ |
C. | A234F₁₆ |
D. | A1111₁₆ |
Answer» C. A234F₁₆ | |
211. |
A twisted ring counter consisting of 4 FF will have |
A. | 4 states |
B. | 8 states |
C. | 2⁴ states |
D. | None of the above |
Answer» C. 2⁴ states | |
212. |
In a shift left register, shifting a bit by one bit means |
A. | division by 2 |
B. | multiplication by 2 |
C. | subtraction of 2 |
D. | None of the above |
Answer» C. subtraction of 2 | |
213. |
The given figure shows a K-map for a Boolean function. The number of essential prime implicants is |
A. | 4 |
B. | 5 |
C. | 6 |
D. | 8 |
Answer» B. 5 | |
214. |
Assertion (A): Gate triggering is the most commonly used method for triggering of an SCR.Reason (R): Even a small gate current is sufficient to turn on an SCR. |
A. | Both A and R are correct and R is correct explanation of A |
B. | Both A and R correct but R is not correct explanation of A |
C. | A is correct but R is wrong |
D. | A is wrong but R is correct |
Answer» B. Both A and R correct but R is not correct explanation of A | |
215. |
The sum S of A and B in a Half Adder can be implemented by using K NAND gates. The value of K is |
A. | 3 |
B. | 4 |
C. | 5 |
D. | none of these |
Answer» C. 5 | |
216. |
In 2's complement addition, the carry generated in the last stage is |
A. | added to LSB |
B. | neglected |
C. | added to bit next to MSB |
D. | added to the bit next to LSB |
Answer» C. added to bit next to MSB | |
217. |
If an inverter is placed at the input to an SR flip-flop, the result is |
A. | T flip-flop |
B. | D flip-flop |
C. | JK flip-flop |
D. | BCD decade counter |
Answer» C. JK flip-flop | |
218. |
The open wired circuit in the given figure works as a |
A. | EX - NOR gate |
B. | AND gate |
C. | XOR gate |
D. | NOR gate |
Answer» D. NOR gate | |
219. |
Assertion (A): Demorgan's first theorem replaces a NOR gate by bubbled AND gate.Reason (R): Double complement of a variable equals the variable. |
A. | Both A and R are correct and R is correct explanation of A |
B. | Both A and R are correct but R is not correct explanation of A |
C. | A is true, R is false |
D. | A is false, R is true |
Answer» C. A is true, R is false | |
220. |
Each cell of a static RAM has |
A. | 4 MOS transistors |
B. | 4 MOS transistors and 2 capacitors |
C. | 2 MOS transistors and two capacitors |
D. | 1 MOS transistor and 1 capacitor |
Answer» B. 4 MOS transistors and 2 capacitors | |
221. |
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 | |
222. |
In 8085 microprocessor, an interrupt service request is serviced |
A. | immediately on receipt of request |
B. | after the execution of the current instruction is completed |
C. | at the end of the current machine cycle |
D. | none |
Answer» C. at the end of the current machine cycle | |
223. |
A 12 bit ADC is operating with 1 μs clock period. Total conversion time is 14 μs. ADC is |
A. | flash type |
B. | counting type |
C. | integrating type |
D. | successive approximation type |
Answer» D. successive approximation type | |
224. |
When a binary adder is used as BCD adder, the sum is |
A. | correct when it is < 9 |
B. | correct when it is > 9 |
C. | correct when it is < 16 |
D. | none of these |
Answer» B. correct when it is > 9 | |
225. |
A 4 bit DAC gives an output of 4.5 V for input of 1001. If input is 0110, the output is |
A. | 1.5 V |
B. | 2.0 V |
C. | 3.0 V |
D. | 4.5 V |
Answer» D. 4.5 V | |
226. |
In INHIBIT operation |
A. | output is 1 when both inputs are 0 |
B. | output is 0 when blocking input is 1 |
C. | output is 0 when blocking input is 0 |
D. | output is 1 when blocking input is either 0 or 1 |
Answer» C. output is 0 when blocking input is 0 | |
227. |
The process of entering data into ROM is called |
A. | writing |
B. | burning |
C. | decoding |
D. | registering |
Answer» C. decoding | |
228. |
The PC contains 0450 H and SP contains 08D 6 H. What will be content of P and SP following a CALL to subroutine at location 02 AFH? |
A. | 0453 H, 08 D 8 H |
B. | 0453 H, 08 D 4 H |
C. | 02 AFH, 08 D 8 H |
D. | 02 AFH, 08 D 4 H |
Answer» E. | |
229. |
The Boolean expression Y = (A + B̅ + A̅B) C̅ then Y will be equal to |
A. | AC̅ |
B. | BC̅ |
C. | C̅ |
D. | none |
Answer» D. none | |
230. |
The Boolean function A + BC is reduced form of |
A. | AB + BC |
B. | A̅B + A̅BC |
C. | (A + B) (A + C) |
D. | (A + C)B |
Answer» D. (A + C)B | |
231. |
A clock signal coordinates the working of different flip flops. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» B. False | |
232. |
In LIFO |
A. | only the top of the stack is immediately accessible |
B. | only the top of the stack is never accessible |
C. | only the first-in is accessible |
D. | only the first-in is not accessible |
Answer» B. only the top of the stack is never accessible | |
233. |
Consider the following digital circuits: 1. Multipliers2. Read only memories3. D-latch4. Circuits as shown in figureWhich of these come under the class of combinational circuit? |
A. | 1 and 2 |
B. | 3 and 4 |
C. | 1, 2 and 3 |
D. | 1, 2, 3 and 4 |
Answer» B. 3 and 4 | |
234. |
Decimal number 9 in gray code = |
A. | 1100 |
B. | 1101 |
C. | 110 |
D. | 1111 |
Answer» C. 110 | |
235. |
A 6 MHz channel is used by a digital signalling system initializing four-level signals. The maximum possible transmission rate is |
A. | 6M bands/s |
B. | 12M bands/s |
C. | 6 M bits/s |
D. | 12M bits/s |
Answer» B. 12M bands/s | |
236. |
The product of which of the following gives the figure of merit of a logic family? |
A. | Gain and bandwidth |
B. | Propagation delay time and power dissipation |
C. | Fan-out and propagation delay time |
D. | Noise margin and power dissipation |
Answer» C. Fan-out and propagation delay time | |
237. |
A presettable counter with 4 flip flops can start counting from |
A. | 0000 |
B. | 1000 |
C. | any number from 0000 to 1000 |
D. | any number from 0000 to 1111 |
Answer» E. | |
238. |
The decimal equivalent of the hexadecimal number (3 E 8)₁₆ is |
A. | 1000 |
B. | 982 |
C. | 768 |
D. | 323 |
Answer» B. 982 | |
239. |
Which multivibrator can be used as a clock timer? |
A. | Astable multivibrator |
B. | Bistable multivibrator |
C. | Any of the above |
D. | None of the above |
Answer» B. Bistable multivibrator | |
240. |
Two 16 : 1 and one 2 : 1 multiplexers can be connected to form a |
A. | 16 : 1 multiplexer |
B. | 32 : 1 multiplexer |
C. | 64 : 1 multiplexer |
D. | 8 : 1 multiplexer |
Answer» C. 64 : 1 multiplexer | |
241. |
Which of the following logic family is fastest of all? |
A. | TTL |
B. | RTL |
C. | DCTL |
D. | ECL |
Answer» E. | |
242. |
Programmable logic array uses |
A. | RAM matrices |
B. | ROMs matrices |
C. | PROM matrices |
D. | Silo memory |
Answer» C. PROM matrices | |
243. |
Out of multiplexer and demultiplexer, which can be used as a logic function generator? |
A. | Multiplexer only |
B. | Demultiplexer only |
C. | Both |
D. | None |
Answer» B. Demultiplexer only | |
244. |
State transition table and state transition diagram form part of design steps for |
A. | combinational circuits |
B. | sequential circuits |
C. | delay circuits |
D. | all of the above |
Answer» C. delay circuits | |
245. |
For the K map in the given figure, the simplified expression is |
A. | A |
B. | B |
C. | C |
D. | D |
Answer» C. C | |
246. |
The most commonly used logic family is |
A. | ECL |
B. | TTL |
C. | CMOS |
D. | PMOS |
Answer» C. CMOS | |
247. |
Assuming accumulator contain A 64 and the carry is set (1). What will register A and (CY) contain after ADI A4H? |
A. | 4 AH, 0 |
B. | 4 AH, 1 |
C. | 4 BH, 0 |
D. | 4 BH, 1 |
Answer» C. 4 BH, 0 | |
248. |
Logic hardware is available only in NAND and NOR. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» C. May be True or False | |
249. |
Flow charts that contain decision symbol |
A. | represent straight line programs |
B. | do not represent straight line programs |
C. | all of the above |
D. | none of the above |
Answer» C. all of the above | |
250. |
The output of the circuit shown below will be of the frequency |
A. | 125 Hz |
B. | 250 Hz |
C. | 500 Hz |
D. | 750 Hz |
Answer» C. 500 Hz | |